Talk of a bipartisan ticket for Florida governor is done, after former congressman Patrick Murphy announced Thursday that he won't run a campaign with a Republican running mate and instead endorsed Gwen Graham in the Democratic primary.

Murphy, a Jupiter Democrat who lost a 2016 bid to unseat Marco Rubio in the U.S. Senate, had kindled speculation for weeks that he'd mount a late-blooming campaign for governor. He polled, raised millions in commitments and launched a media campaign with former Republican congressman David Jolly based around a call for civility and compromise in America's increasingly polarized political world.

But at a local political event in Pembroke Pines, Murphy said he decided against it Wednesday night. He said he raised enough money to mount a campaign, but said "a combination of factors," including a friendship with Graham born during their time together in Congress, swayed him in the opposite direction.

"I did put a lot of thought into it. It was a very difficult decision. One of the toughest things that Gwen and I talked about was that personal relationship. You never want to run against a friend. That stinks," he said. "I thought maybe bringing a Republican and Democrat together might be a unique way to actually solve problems."

Murphy's decision not to run has real consequences for the Democratic primary for governor. The race already features Tallahassee Mayor Andrew Gillum, Graham, Winter Park businessman Chris King and former Miami Beach Mayor Philip Levine. On Friday, billionaire tycoon Jeff Greene also entered the race.

A Murphy candidacy would have further muddied the waters for voters, many of whom remain undecided. Instead, though endorsements typically do little to move the needle, Murphy could give Graham a boost as he said he'd do his best to encourage his financial backers to put their money behind her. Polls have shown Graham in a crowd for second place behind Levine, but her campaign went on television for the first time Wednesday and she's increasing her spending on digital ads.

"This is a big day for our campaign. A monumental day," Graham told the audience at Century Pines Jewish Center.

Graham billed the endorsement as a sign that Democrats are "coming together."

On the other hand, Graham's union with Murphy — with whom she left open the possibility of running on a ticket — does appear to move her further to the center in a primary where most of the candidates are running to the left. During a brief speech, Murphy said Graham "has got the proven track record to get results in Tallahassee, to find that middle ground to get things done."

After Politico broke the news of Murphy's endorsement, Gillum spokesman Geoff Burgan asked if "it comes with David Jolly's endorsement too?" — a jab at Graham's oh-so-brief public contemplation that she, too, might be willing to run with Jolly.

Graham, who represented a right-leaning North Florida district during her time in Congress, dismissed those jabs Thursday, saying she and Murphy are focused on results. She also said polls that show her trailing far behind Levine in major Democratic markets in South Florida and Tampa don't jibe with her own internal polling. On Thursday, Democratic pollster Tom Eldon released a South Florida poll for a group he said is not involved in the race that showed Graham with 11 percent support in Broward and 4 percent in Palm Beach County. Levine, who's contributed millions of his own money to his campaign that’s been on television for months, pulled 38 and 40 in the poll, respectively.

"Those polls are not aligned with what our polling shows. I don't worry about polls," Graham said. "Absolutely the fact that we got up on TV yesterday, I think this is a turning point, monumental point, in our campaign. And having congressman Murphy's endorsement today is just another part of that coming together of Democrats."

Eldon said he, too, expects Graham to go nowhere but up.

"This is probably the last time we'll ever see Gwen Graham single digits in the polls," Eldon said. "I don't think this is in any sense a prediction of where Gwen Graham is going to finish up."