Campaign finance reports illuminate the state of the race to replace Sen. Ben Cardin (D), who is retiring, as the May 14 primary approaches.

A month ahead of the primary election that will set up Maryland’s race for an open U.S. Senate seat, campaign filings show millions of dollars pouring into candidates’ coffers — including big donations from national groups banking on the seat’s significance for control of the chamber.

The large fundraising sums, from financial reports due Monday, reflect the escalating attention on what had largely been seen as a sleepy contest for a reliably blue seat until former Maryland governor Larry Hogan (R) launched a surprise bid two months ago.

Hogan, whose favorability among voters has remained high even after leaving office in 2022, led his potential Democratic opponents in a March Washington Post-University of Maryland poll, though many voters said they were undecided.

Hogan will probably face either Prince George’s County Executive Angela D. Alsobrooks (D) or Rep. David Trone (D-Md.) in November’s general election. He has raised more than $1.9 million in two months, plus another $1.2 million collected by two political action committees associated with his campaign — for a total of over $3.1 million, signaling a tough and expensive battle after the primary.

“Our team is incredibly humbled and grateful for the overwhelming amount of support and positive reception we have received across the state since announcing mid-February, and we are just getting started,” Hogan said in a statement announcing his fundraising figures last week. “In a race where we are likely to face either the billionaire trying to buy the election or the candidate of the Democratic machine, there is no doubt we are the financial underdog too.”

Trone, co-owner of the multibillion-dollar alcoholic beverage retailer Total Wine & More, far exceeds both Alsobrooks and Hogan in resources.

A largely self-funded candidate, Trone has brought in $640,168 in individual contributions and has loaned his campaign $41.7 million since the start of the primary race, federal campaign finance records show. His campaign has just shy of $1 million on hand after spending $41.8 million on operating expenses such as advertising, staffing and paying back some of those loans.

“Voters across the state continue to respond to David Trone’s proven track record as the only candidate who can put people over politics and deliver real change in the United States Senate,” campaign spokesman Joe Bowen said in an emailed statement. “David Trone is the only candidate with the message and resources to take on Larry Hogan in November and we look forward to continuing to communicate with voters across the state as the primary approaches.”

The March Post-UMD poll showed Trone leading Alsobrooks in the contest to replace Sen. Ben Cardin (D-Md. ), who is retiring: 34 percent of registered Democrats support Trone, while 27 percent prefer Alsobrooks. As of last month, the primary remained wide open, with nearly 4 in 10 Democratic voters — 39 percent — not yet picking a primary candidate.

Alsobrooks, who has brought in more individual contributions than any other candidate so far, has raised more than $6.1 million since the start of her campaign, including $1.2 million since January. Her campaign has already spent $3.9 million, leaving Alsobrooks with just under $3.2 million on hand.

“Angela has this race in a dead heat despite being up against the biggest self funder in a Senate primary in American history,” Alsobrooks campaign spokeswoman Gina Ford said in a statement. “That fact alone speaks to the strength of her candidacy, her impressive grassroots movement, and the genuine excitement around her as we go into this final month.”

The general election will plunge candidates into a national battle for majority control of the U.S. Senate, which Democrats now hold by a razor-thin margin. Though a Republican hasn’t represented Maryland in the Senate since 1987, Hogan’s popularity in the state may present an opportunity for the GOP to flip a long-blue seat. Still, Hogan would have to overcome attacks on his positions on key issues like abortion access, which did not play as prominent a role in his campaigns for governor but will be front and center in a year when Marylanders will also be asked to enshrine abortion rights in the state constitution.

Records show Hogan’s campaign is already drawing support from national GOP players, including from the National Republican Senatorial Committee and political action committees affiliated with more than a dozen sitting Republican senators, and from prominent Republican donors like Harlan Crow, the Texas billionaire who was thrust into headlines because of his close relationship with Supreme Court Justice Clarence Thomas.

Hogan’s potential challengers are already using his donors to draw a distinction between the popular Republican and the Democrats he may face in the general election.

“As we look towards November, it’s no surprise Larry Hogan is raising money from MAGA donors to try and pad his coffers,” said Ford, the Alsobrooks campaign spokeswoman. “Angela will defeat him.”

Other congressional races in Maryland are also drawing in substantial funds. In the Democratic primary for the 3rd Congressional District, former Capitol Police officer Harry Dunn has raised more than $3.7 million since announcing his campaign in January. His top opponent, state Sen. Sarah K. Elfreth (D-Anne Arundel), has raised $915,685 since the start of her campaign. The candidate with the third-highest fundraising total was state Sen. Clarence K. Lam (D-Howard), who raised $639,868.

In the 6th Congressional District’s Democratic primary contest for the seat vacated by Trone, former Biden administration official April McClain Delaney has raised $1.3 million since the start of her campaign, including a $550,000 loan she made to the campaign. Her husband, businessman John Delaney, held the seat from 2013 to 2019. State Del. Joe Vogel (D-Montgomery) has raised $610,790 and Hagerstown Mayor Tekesha Martinez has raised $322,644.