Could a Republican win a U.S. Senate seat in Maryland? Usually, the answer would be no: The state is one of the bluest in the country, and a Republican hasn't won a Senate election there since 1980. But the last Republican to win statewide office in the Old Line State is looking to buck partisan forces again. Last month, former Gov. Larry Hogan announced a campaign for the seat held by retiring Democratic Sen. Ben Cardin, which has unexpectedly added Maryland to the list of potentially competitive Senate races in 2024.

Hogan has the credentials to make this race far more interesting than it would have been otherwise. The popular former governor would need to win over a meaningful share of moderate Democrats or independents who typically back Democratic candidates — a coalition critical to his successful gubernatorial bids in 2014 and 2018, and a must for any Republican to win in Maryland. Early polls suggest he could do just that, in a race against either Democratic Rep. David Trone or Prince George's County Executive Angela Alsobrooks, the two leading Democratic contenders.

But Hogan will also face a major obstacle: sharing the ballot with former President Donald Trump. The GOP's presumptive presidential nominee lost Maryland by 26 and 33 percentage points in 2016 and 2020, respectively, and he will almost certainly lose the state by a sizable margin to President Joe Biden in 2024, too.

To win, Hogan will have to separate himself from Trump and attract a large share of split-ticket voters, which has become increasingly difficult in a political era where most voters support the same party for president and Senate. This election will feature a clash between the highly nationalized, polarized and partisan politics that dominate today's political landscape and the idiosyncrasies of Hogan's personal appeal. The challenge for Hogan is that the former usually wins out in Senate elections these days.

Hogan is the best the GOP could hope for in Maryland

At the very least, Hogan has given Republicans an actual shot in this race. Following Hogan's entry, election observers at Inside Elections, Sabato's Crystal Ball and The Cook Political Report all moved the outlook for Maryland from solid/safe Democratic to the peripherally competitive "likely Democratic" rating. That means they still view Hogan as an underdog, but his candidacy has put Maryland in the mix of roughly 10 Senate races (out of 34 this cycle) where each party has more than a marginal chance of winning. But even if Hogan goes on to lose, his campaign could compel Democratic-aligned groups to spend money in Maryland that they'd prefer to spend elsewhere.

Looking at the early polls, Hogan may feel more bullish about his chances than the election handicappers do. So far, he's led in most surveys testing him against Trone or Alsobrooks, who will face off in the state's May 14 primary. (Hogan also has primary competition that day, but looks likely to win.) Across four surveys conducted since last fall, Hogan has led Trone by an average of 3 points, while he's had an average lead of 13 points against Alsobrooks.

Now, there are a number of reasons we'd caution against reading too much into Hogan's lead in this handful of early polls. First, the wide variation in outcomes here reflects the reality that the election is still more than seven months away. Notably, two of the surveys came from partisan pollsters, and each of those was conducted before Hogan announced his bid. One was a poll from Ragnar Research Partners conducted on behalf of Hogan's campaign just ahead of his announcement that found Hogan particularly far ahead. The other, conducted all the way back in November, came from Victoria Research for a Democratic lobbying firm, and it featured far and away the largest gap between how Trone and Alsobrooks performed against Hogan.

Nonetheless, more recent nonpartisan surveys from Emerson College/The Hill/DC News Now and the Washington Post/University of Maryland Center for Democracy and Civic Engagement also found Hogan either tied or leading his two potential Democratic opponents. Similar to the partisan polls, Emerson found Hogan polling 8 points better against Alsobrooks than against Trone. Meanwhile, the Washington Post/University of Maryland survey found him polling similarly far ahead of both Democrats with around 50 percent support. That's an important threshold — 50 percent plus 1 vote guarantees a win, after all — and we'll be keeping an eye on whether Hogan can keep getting close to that mark as the campaign wears on.

That brings us to another important note in understanding these early polls: At this point in the race, Hogan has much higher name recognition than either of his two potential Democratic opponents, which could play into his edge over them. In the Washington Post poll, nearly 9 in 10 Maryland voters had an opinion (positive or negative) of the former governor, compared to just over half for Trone and around 2 in 5 for Alsobrooks.

This familiarity differential could also help explain why Hogan has a smaller polling lead over Trone than over Alsobrooks: The personally wealthy Trone has vastly outspent Alsobrooks in the primary, though the latter leads the state's second-most populous county and has attracted support from many high-ranking Maryland Democrats. But whoever of the two emerges victorious from the May primary can be expected to pick up name recognition and, presumably, wider support as the campaign wears on.

Beyond the topline numbers, these surveys also reveal some of the strengths that give Hogan a chance of overcoming Maryland's blue lean. Hogan has appealed to Democratic-leaning moderates and even some liberals since he pulled off a surprising win in 2014, and he left office as one of the most popular governors in the country. The Washington Post/University of Maryland poll found that 64 percent of registered voters held a favorable view of Hogan, including 52 percent of self-identified liberals and 73 percent of moderates. In the same survey, he had an eye-popping 61 percent favorability rating among Democrats. Across the two nonpartisan polls, Hogan led among independents by more than 20 points and attracted 25 to 33 percent of Democrats, all while holding most of the Republican base. (The latter was true even though Hogan's favorability among Republicans in the Washington Post/UMD poll was only 67 percent, on par with independents and only slightly above Democrats.)

The weight of partisanship could sink Hogan

However, maintaining enough separation from Trump to win over a substantial share of Biden voters is where things will get sticky for Hogan. The former governor's active opposition to Trump has been a notable part of his success in blue Maryland and allowed Hogan to largely avoid being lumped in with him like other Republicans. Hogan repeatedly criticized Trump during his presidency: He was one of only a few nationally prominent Republicans who backed the first impeachment inquiry against Trump in 2019, and he also supported convicting Trump in his second impeachment related to the then-president's actions on Jan. 6, 2021. After leaving office, Hogan even considered running against Trump for the 2024 Republican nomination, but instead worked as part of the bipartisan group No Labels to develop a still-unsettled third-party presidential bid. Since declaring his Senate run, Hogan has said that he won't vote for Trump this November, in line with his write-in votes for Ronald Reagan in 2020 and his father in 2016.

But over the past few decades, politics have become more nationalized amid increased political polarization and growing antipathy toward political opponents (known as "negative partisanship"), which have pushed voters more firmly into one party's camp or the other. This has made it tougher for candidates to build a brand distinct enough from their party label to overcome the partisan lean of their state. As a result, both Senate and gubernatorial elections have become more nationalized and more partisan, making it harder for a Democrat to win in a red state and a Republican in a blue state. And while Hogan managed to pull it off in two gubernatorial contests, garnering split-ticket votes in a Senate race during a presidential year is likely to be tougher.

One simple way of gauging this is measuring how often the same party won the presidential and Senate elections in states that had both races on the ballot. Back in 1988 — the start of a four-decade run of highly competitive presidential elections — only about half the states with a Senate race backed the same party for president and Senate. That figure grew to around 70 percent by the start of the new millennium. But in 2016, every state with a Senate contest backed the same party for both offices. Four years ago, just one state had a split outcome: Maine, where Republican Sen. Susan Collins won reelection by 9 points even as Biden carried the state by about the same margin.

This trend in parallel presidential-Senate outcomes is actually a positive for Republicans this cycle, as it could help them capture three Democratic-held seats in Montana, Ohio and West Virginia. Each state is likely — or certain — to back Trump for president, so Democratic Sens. Jon Tester and Sherrod Brown in Montana and Ohio, respectively, will have to substantially outperform Biden to have any shot at winning (West Virginia flipping to the GOP is essentially a given following Sen. Joe Manchin's retirement).

But the same challenge exists for Republican candidates running in states with a Democratic lean. For instance, election handicappers give Republicans little chance of winning Senate races in light blue states like Maine, Minnesota and Virginia, which are much more politically competitive than Maryland overall. (Granted, all three of these contests feature incumbents running for reelection.) That Maryland is considered more up for grabs than those states speaks to Hogan's strength as a candidate, but he'll have to overcome the same forces at work elsewhere. It's no coincidence that Maryland Democrats are looking to nationalize the race by emphasizing Hogan's party connection to Trump and Hogan's opposition to abortion. While such attacks didn't overcome Hogan in his gubernatorial races, they could be more potent in the federal arena, particularly with control of the Senate at stake.

The reality behind this trend is that there are just fewer split-ticket votes being cast in federal elections, which we can see by comparing vote margins in concurrent presidential and Senate races. In 2000 and 2004, the median difference in the margins of victory for presidential and Senate races occurring in the same state was more than 12 points. But that figure dipped below 3 points in 2020, showing how similar presidential and Senate results have become.

As a result, presidential and Senate vote margins increasingly have a very strong relationship to each other. In 2020, the correlation between the two sets of results was 0.95 on a scale that maxes out at 1, the highest correlation between presidential and Senate results in the post-World War II era. Correlation isn't causation, but we know the strong pull of partisanship in our polarized age has helped make this happen.

To put Hogan's challenge in even sharper relief, let's examine how rare it is nowadays to best your party's presidential nominee by the kind of margin Hogan likely needs to have a shot at victory. Recent Maryland surveys found Biden ahead of Trump by a little more than 20 points head-to-head, and by the upper teens when independent candidate Robert Kennedy Jr. was included as an option. If Biden were to win Maryland by at least 20 points — a substantial drop from his 33-point edge in 2020 — Hogan would need to outperform Trump by at least 10 points to win. Dating back to 2012, only 11 candidates have outperformed their party's presidential nominee by that much in states that their party lost in the race for the White House.

At the top of this list is Manchin, who in 2012 essentially reversed President Barack Obama's losing margin, outrunning the Democratic presidential ticket in West Virginia by about 51 points in the process. Four other notable red-state Democratic senators who won in 2012 also made the list by significantly outperforming the party's presidential ticket to narrowly win — but of those, only Tester survived to win reelection in the 2018 midterms. Meanwhile, Collins's aforementioned split-ticket result in Maine is the only entry from 2020.

Sharp-eyed observers might notice one popular ex-governor on this list who might be roughly analogous to Hogan. In 2012, former Hawaii Gov. Linda Lingle, a Republican, challenged the Aloha State's blue status quo in an open-seat contest but lost by 25 points, even as she ran about 18 points ahead of Mitt Romney's 43-point loss. Hogan looks more likely to be competitive than Lingle, but her performance, as well as that of other recent former governors who ran for Senate like Democrats Steve Bullock (lost in Montana's 2020 race) and Phil Bredesen (lost in Tennessee's 2018 contest), speaks to the difficulties of transitioning from a winning gubernatorial candidate to a winning senatorial contender in a state where your party is in the clear minority.

The long and short is that Hogan will almost certainly need to win over a critical mass of split-ticket voters in an era when that is less and less common. He has the potential to do this, given his moderate profile and past success in Maryland. But betting on partisanship over personal appeal in Senate races, particularly in presidential years, has been a pretty good wager in recent years.