U.S. Senate candidate Angela Alsobrooks is getting a boost from one of the biggest names in Democratic politics: former President Barack Obama.

The Alsobrooks campaign released a 30-second ad on Friday featuring an endorsement from the 44th president.

“Control of the Senate could come down to Maryland, so vote for Angela Alsobrooks,” Obama says in the ad.

He touts her record of reducing crime as a prosecutor, and says she would put Marylanders first in the Senate. “In the Senate, Angela will fight for you. She will work to lower costs and lead the fight to protect our democracy and our freedoms,” Obama says.

Alsobrooks, a Democrat who is currently the Prince George’s County executive, is facing Republican former Gov. Larry Hogan for Maryland’s open Senate seat after longtime Democratic Sen. Benjamin L. Cardin opted not to run for reelection.

The race between Alsobrooks and Hogan has drawn national attention — rare for Maryland — because the outcome could help determine which party controls power in the U.S. Senate, a fact referenced by Obama in his endorsement video.

Democrats currently have a narrow 51-49 margin in the Senate, and they’re likely to lose at least one seat, West Virginia, in this year’s election, putting pressure on competitive campaigns in states like Maryland.

Though recent polls show an advantage for Alsobrooks, Hogan is a formidable candidate who remains popular after two terms as governor. Both campaigns, and their respective parties, see an opportunity to win in Maryland.

To that end, Alsobrooks has branded her campaign trips around the state as the “Defend Our Majority Tour.” On Thursday, her campaign bus was parked at Bowie State University, where she and allies Gov. Wes Moore and U.S. Rep. Steny Hoyer encouraged students to vote to ensure that Democrats can hold the Senate majority.

“Whoever’s in the majority in the Senate — whether it’s the Democratic Party or Republican Party — controls the agenda for our country, controls whether or not we have reproductive freedoms, controls whether or not we even get to vote to have sensible gun legislation,” Alsobrooks said. “And because we are about to — Hallelujah! — elect Kamala Harris to be president of the United States of America, when Kamala is elected president, she’s going to have to have a Senate that will support her.”

Alsobrooks has seen a number of top Democrats supporting her campaign. Before Harris became the presidential nominee, the vice president campaigned twice with Alsobrooks this summer. U.S. Sen. Amy Klobuchar of Minnesota joined a door-knocking effort in Towson last weekend, and U.S. Sen. Elizabeth Warren of Massachusetts recently visited with volunteers in Silver Spring.

Hogan also has a former president in his corner, though he has not appeared thrilled about it. Former President Donald Trump, who is running again, gave an endorsement for Hogan in a news interview earlier this year.

Hogan brushed it off and has repeatedly said he would not return the favor and vote for Trump.

The Washington Post first reported Obama’s endorsement of Alsobrooks.