Florida senator Marco Rubio made one of his most definitive and direct statements in support of Donald Trump yet during a candidate forum this weekend, all but sloganeering the words "elect Trump".

"We have got to come together as a party. We cannot lose to Hillary Clinton. We cannot lose the White House," Rubio said on Saturday, reports the Sarasota Herald-Tribune. Then came the money line: "We have to make sure that Donald wins this election."

Rubio's call for Republicans to rally to Trump comes after the one-time White House hopeful ripped Hillary Clinton's speech at the Democratic National Convention in real time Thursday. "So basically [the] 'change' Hillary offered is same Obama agenda but with more taxes, more [regulations], and an 'intelligence surge', whatever that means," he tweeted as Clinton concluded her address in Philadelphia.

He also accused the Democratic nominee of "[accepting] socialism as her cause," upon Clinton espousing Bernie Sanders's agenda in unambiguous terms. "Your cause is our cause," she told the Vermont senator Thursday.

Alongside his anti-Clinton stance, however, Rubio has become more pro-Trump in recent months, even if by default. "I want to be helpful. I don't want to be harmful, because I don't want Hillary Clinton to be president," he told CNN in late May. "Look, my policy differences with Donald Trump, I spent 11 months talking about them."

As it has been with many of Trump's vanquished primary rivals, though, the personal differences were the bigger issue. The man the eventual GOP nominee dubbed "Little Marco" and something called a chocker was provoked to mock Trump on the campaign trail as Rubio's electoral odds faded. Rubio said during the CNN interview that he privately apologized to Trump for saying he had "tiny hands".

Trump has since warmed to Rubio, amid word that the one-termer was considering a last-minute bid to run for reelection. "Poll data shows that Marco Rubio does by far the best in holding onto his Senate seat in Florida. Important to keep the MAJORITY. Run Marco!" he tweeted May 26.

Rubio—who Trump now calls a "good guy"—ultimately jumped into the race.