But it may be too late, with anger toward all of them running deep among Carson's base.
"We have (some supporters) that would just as soon lay under the bus than support (Ted) Cruz, or (Donald) Trump, or in some cases (Marco) Rubio," said John Philip Sousa IV, national chairman of the pro-Carson super PAC 2016 Committee.
At one point, support for the Texas senator ran strong among Carson's backers. But, Sousa said, after Cruz's campaign sent information to precinct captains during the Iowa caucuses that Carson was suspending campaigning, Carson's backers have had a hard time letting go of what the candidate decried as "dirty tricks."
"I had an email this morning from a volunteer ... saying, 'Gee, we love Dr. Carson, we hope he gets out and moves his support to a really, good honest, Christian conservative: Ted Cruz.' And I'm scratching my head and going, honest? How does that fit in there with what Cruz did to Carson?" Sousa said.
"Some people are so angry at Cruz they could spit nails. They wouldn't support him if he were the last guy on earth after what he did to us," he added.
Sousa was reacting to a statement put out by Carson early Wednesday afternoon saying he acknowledged there is no "political path forward" for his campaign -- though he did not formally suspend his bid. Carson will say more at a Friday speech before conservatives in Washington.
Each campaign still in the race can complain that Carson is a spoiler, and will argue that they are likely to pick up his support. Trump and Cruz have made the biggest connections with deeply religious voters that have flocked to Carson, but the Rubio campaign hopes to be a dark horse for Carson's voters after what Cruz's campaign did in Iowa and after Trump relentlessly mocked Carson's life story last year.
In Virginia on Tuesday, Carson got nearly 6% of the vote. Rubio only needed 2.9 percentage points there to beat Trump. In Arkansas, Carson again got nearly 6% of the vote. Cruz needed 2.3 percentage points there to pull ahead of Trump. And in Vermont, Carson got 4.2% of the vote, nearly double the 2.4 percentage points John Kasich would have needed to overtake Trump.
Kasich was the first candidate to tell voters on Wednesday that he spoke to Carson after he made his announcement.
"I just had a very, very nice conversation with Dr. Ben Carson," Kasich said. "I think he held his head high and he's a very, very good man."
Sousa, however, discounted the likelihood Kasich would pick up any Carson supporters even more than the three top candidates.
"Kasich, I don't think he's got a snowball's chance in hell," Sousa said, saying he should stay put as governor. "Good guy, great governor for Ohio."
He added it's too soon for many in Carson's orbit.
"There's going to be a lot of wet pillows tonight of people sobbing because Carson's out of it," he said. "And I think if Ted Cruz or any of them, quite frankly, came to us today and said, 'We want to rent your (contact) list,' I'd say, 'No. Our people aren't ready to hear from you.'"
But Carson's close confidante and business adviser Armstrong Williams went further, saying not only should none of the non-Trump candidates expect Carson's support, they should follow his lead.
"If Cruz or Rubio are going to get elected it has to be on their own merit," Williams said. "It's just a matter of time before Ted Cruz and Marco Rubio come to the same conclusion as Dr. Carson: there's no pathway for them to get the nomination."
Williams repeatedly answered a question about a potential Carson endorsement by saying that Carson would support whoever eventually became the nominee -- and predicted that would be Trump.
"Everyone needs to come to the realization that Donald Trump will be the nominee when it's all said and done," Williams said. "I know they're saying they have the best chance of toppling Trump, but let's admit it, they have no pathway either. ... Since Iowa he has been steamrolling."