The 44th president has raised more than $13 million for Democrats this cycle.

With less than a month until Election Day, former President Barack Obama is sharply increasing his role in the midterm elections, raising money, cutting ads and hitting the campaign trail as Democrats press into territory he says he never expected to compete in.

At a Democratic Senatorial Campaign Committee (DSCC) fundraiser held in Virginia on Wednesday, the former president told donors the Senate map now includes states like Texas that he "would not have imagined being in play," according to excerpts of his remarks reviewed by ABC News. He also cautioned that every one of those races could still slip away.

“I don’t want anybody to think this is a sure thing. It’s not,” he said alongside Sen. Lisa Blunt Rochester, D-Delaware, a vice chair of the DSCC. “We could end up, all these races that are showing we’ve got a two- or three-point lead or it’s a tossup, we could end up losing all of them by two points." He described the outcome as "on the razor's edge." Kansas, Nebraska and Sen. Jon Ossoff’s lead in Georgia also made his list of surprises.

The fireside chat event raised $3.6 million, according to Obama's office, which it said brings his total for party committees this cycle to $13.6 million. Obama's involvement extends well beyond fundraising and also includes him making direct appeals for candidates.

Over the past two days, ads or endorsement videos have rolled out for gubernatorial candidates Josh Shapiro in Pennsylvania, Keisha Lance Bottoms in Georgia, Deb Haaland in New Mexico and David Crowley in Wisconsin. Senate candidates featured so far include Ossoff and Troy Jackson in Maine.

The Democratic National Committee launched a new series of ads Friday in a six-figure digital buy, in which Obama urges Democrats to "get involved." The ads add to Obama's campaign appearances in Texas, where stumped with Senate candidate James Talarico and gubernatorial candidate Gina Hinojosa in Austin, and he appeared in an ad in Iowa with Senate candidate Josh Turek in July.

He is scheduled to campaign next in Michigan for Senate nominee Abdul El-Sayed and Jocelyn Benson, who is running for governor. That stop will put Obama alongside El-Sayed, one of the party's most progressive candidates. Obama used Wednesday's fundraiser to defend the breadth of the Democrats “big tent.”He joked that leading the party is "a pain in the butt" because of how wide a range of ideological views it holds.

“I’m going to go to Michigan to campaign for Abdul El-Sayed. And people are like, ‘Well, he’s really left-wing.’ But I don’t know, he’s for a higher minimum wage and healthcare for all, and it doesn’t seem crazy to me. You know, FDR was for that, too,” Obama said at the DSCC fundraiser.

In the same remarks, Obama praised Turek, who is running in a state President Donald Trump won comfortably in 2024, for focusing on farmers hurt by tariffs and the Iran War.

“Any place, politics starts with people feeling as if they are seen,” Obama advised.

According to an NBC News poll conducted in mid-September, 30% said they’d be more likely to vote for a candidate endorsed by Trump, but 52% said they’d be less likely. In comparison, 43% said they’d be more likely to vote for a candidate endorsed by Obama, 37% said they’d be less likely.

Obama remains the party's most in-demand surrogate and his expanding schedule signals how much Democrats are counting on him to energize voters in the final weeks.