Less than two months ago, Brent Welder was tweeting “#DropOutWarren” at the Massachusetts senator trying to overtake Bernie Sanders in the 2020 progressive lane.

Now the former Kansas congressional candidate is waiting to see if Elizabeth Warren, who officially ended her presidential run Thursday, sides with the Vermont Independent he strongly supports as the 78-year-old tries to recapture a sense of frontrunner momentum.

"I don't think there needs to be any rush," Welder said. "And I do ultimately believe that she’ll do the right thing."

Welder is among the Sanders supporters hoping Warren will join the progressive’s cause amid a tough calendar of primary contests that could further put the senator at a disadvantage against former Vice President Joe Biden.

Michigan, Missouri, Idaho, North Dakota, Washington, and Mississippi will all vote March 10, and special attention is already being paid to the Midwestern voters. Michigan’s status as a general election flashpoint makes it a crucial proving ground for the remaining 2020 contenders.

"He needs a big comeback next Tuesday," said longtime Democratic strategist Mark Longabaugh, who previously worked for Sanders in 2016 but switched to businessman Andrew Yang this cycle.

"You’ve got to focus on Washington state and you've got to focus on Michigan, maybe a little bit less so on Missouri. But I think you’ve got to win those two states that you carried last time."

In Michigan, Biden won the endorsement of Gov. Gretchen Whitmer on Thursday and announced plans to dispatch former 2020 rival Sen. Amy Klobuchar (D-MN) for events on Friday and Saturday before the former vice president’s event in Detroit on Monday. Sanders, who won the state in 2016, has events scheduled for Friday and Sunday.

But Warren’s departure doesn’t mean her supporters will uniformly flood to Sanders, a reality that some of the Vermont Independent’s strong supporters quickly acknowledged.

"I would say that I really hope that we can earn their support and we really stand with them on so many issues that I hope we can earn their support," said Michelle Deatrick, a Democratic National Committee member from Michigan who is backing Sanders. "But we respect their decisions."

Chris Savage, chairman of the Washtenaw County Democratic Party in Michigan said it was presumptuous for some from the Sanders orbit to assume he’d join with Sanders just because he supported Warren.

Savage, who described himself as "radically left progressive, for the most part," said he endorsed the Massachusetts senator in his personal capacity and is voting for Biden.

"I'm voting on electability quite frankly and I don't think that Bernie Sanders can beat Donald Trump," Savage said.

Robert Mijac, a Democrat on Michigan's Macomb County Board of Commissioners who endorsed Warren, was stoic about his chosen candidate leaving the race Thursday. He, too, said he’ll probably vote for Biden when the primary comes.

"I like Bernie, but I think Biden’s going to have a better chance at beating Trump by far," Mijac said. "I don't think Bernie—with the whole socialist thing—I don’t think that works well here."

Gripes with Warren from some Sanders endorsers are also apparent as he plays catch-up with Biden.

Curtis Wylde, a professional wrestler and DNC member from Missouri who supports Sanders, derided the moderate grouping around Biden as a “centrist Megazord,” and feels that Warren should have dropped out and endorsed Sanders.

"I see Biden as a very flawed candidate," he said. "As flawed as Hillary Clinton, without as much excitement." He believes Donald Trump is "probably going to eat him for breakfast."

But with Missouri’s primary approaching, he said he would have liked to have seen more of a Sanders ground game in his state.

"I honestly don't feel the wave in Missouri towards Bernie that I did in 2016," he said. "Not that I don’t feel it. I don’t see it. I don't see the noticeable emotion from people or the support that I had seen. Although, that said, I don't see that for anyone here in Missouri."

Earlier this week, the groundswell of support that catapulted Biden was almost immediately used as a subtle example by one of Sanders’ most prominent surrogates of what could have happened for progressives.

“Imagine if the progressives consolidated last night like the moderates consolidated, who would have won?” Rep. Ilhan Omar (D-MN) tweeted late on Super Tuesday when Biden re-solidified his frontrunner status.

After largely avoiding confrontation in earlier debates, hard feelings between Warren and Sanders became more clear as the primary season took shape.

Warren sparred with Sanders in January over whether the Vermont Independent had told Warren during a 2018 meeting that a woman couldn’t beat Trump this cycle (something Sanders has denied). As her campaign began to struggle, Warren took further shots at her fellow progressive but it couldn’t help save her run.

Warren’s decision to avoid making a sharper contrast with Sanders earlier was seen as a strategic mistake by some that loomed large as she tried to find her way to victory in what was once a vast Democratic field.

During the 2016 cycle, Warren held off from endorsing Hillary Clinton until the primary between the former Secretary of State and Sanders was essentially over.

Warren did not immediately endorse a candidate after ending her bid Thursday, a contrast to her moderate rivals who quickly moved to Biden’s side after they dropped out ahead of Super Tuesday.

"(I) want to take a little time to think a little more," Warren said about declining to endorse on the day she dropped out.

Warren continued to demur on an endorsement during an interview with MSNBC’s Rachel Maddow Thursday night.

“I’ll get up tomorrow morning and start thinking about that question,” Warren said.

Pressed by Maddow about if waiting to endorse could lessen the impact of an eventual endorsement, Warren remained focused.

“It’s only been a day,” Warren said. “Just give me a little space here.”