More than 30 Democratic senators are hosting a fundraiser for South Dakota Democratic Senate candidate Rick Weiland next month.

The fundraiser comes even as the Democratic Senatorial Campaign Committee (DSCC) has been reluctant to embrace Weiland's candidacy, though he's currently the only Democrat in the race.

Notably missing from the invitation is DSCC Chairman Michael Bennet (D-Colo.), who said earlier this year that the committee is still searching for a candidate in South Dakota.

Sen. Tim Johnson (D-S.D.), whose retirement opens up a top pickup opportunity for Republicans in the increasingly red state, is the primary host of the event.

He's endorsed Weiland and, in a letter to supporters accompanying the fundraiser invite, obtained by The Hill, praised the candidate as "a practical progressive, the kind who knows how to win."

Of himself and the three Democratic Senators elected in South Dakota before him, Johnson writes: "Each of us began with a good car, a firm handshake, and a willingness to use them both every single day for well over a full year."

"Rick Weiland is going to be South Dakota's next United States Senator because he got in his car last July and he hasn't been out of it since," he adds, noting Weiland's aggressive fundraising schedule.

Tickets to the Dec. 10 fundraiser range from $5,000 for a host to $500 for a guest.

Hosts include New York Sen. Kirsten Gillibrand and three of the Senate's most vulnerable Democrats: Sens. Mark Begich (Alaska), Mark Pryor (Ark.) and Mary Landrieu (La.).

Weiland, who entered the race after the two preferred candidates, U.S. Attorney Brendan Johnson and former Rep. Stephanie Herseth Sandlin, declined to run, has struggled to gain traction.

He finished the last fundraising quarter with just $315,000 cash on hand after raising about $170,000 over three months.

The GOP snagged a top recruit in former Gov. Mike Rounds.

Democrats hope Rounds will take a beating from his three primary opponents in the coming months. But to take any advantage of a weakened Republican candidate in the general, the party needs a formidable Democratic opponent.

Democrats remain skeptical that Weiland is that opponent, as he's largely a political newcomer — he launched two failed congressional bids and served as an advisor to former Senate Majority Leader Tom Daschle (D-S.D.) — and is running a relatively progressive campaign for a red state.

But the fundraising help from more than two dozen Senate Democrats is likely to give him a boost, as it's a signal the party is beginning to coalesce behind him.