Days before Super Tuesday, when 12 states and one territory cast their votes, the Florida senator has turned his campaign into a riposte to Trump’s dominance in the Republican field. But unlike the half-dozen candidates who have followed similar routes, Rubio is aiming to beat Trump at his own game.

Peppering his stump speech with broadsides at the front-runner, Rubio has called Trump a hypocrite, accused him of weakness, and even questioned his manhood. “You know what they say about men with small hands,” Rubio said in Roanoke Sunday evening, complete with a pregnant pause. “You can’t trust ‘em.”

Beaming ear-to-ear as he delivered the crude taunt, Rubio is the first GOP candidate to appear to relish in taking on Trump. “We gotta have fun with it,” he says, before launching into yet more slurs. “Donald is not going to make America great, he’s going to make America orange,” Rubio said, mocking Trump’s alleged spray tan. Noting Trump received medical deferments to avoid serving in Vietnam, Rubio struck again. “He didn’t serve…because he got injuries from playing squash,” Rubio said. “He’s not a tough guy.”

With Trump expected to take the largest share of delegates on Tuesday, opening up a significant lead on the remaining candidates, the stakes for derailing the bombastic candidate have never been higher. “We have to rally now not just to stop Donald Trump, but to save the conservative movement,” Rubio said.

The do-or-die effort to take on Trump has given the campaign “a real sense of purpose,” Rubio senior adviser Todd Harris said.

The single-minded focus risks Rubio’s candidacy becoming more about who he is running against, rather than what he is for. But in a media environment that appears to reward one-liners at the expense of policy, Rubio is looking to take a page from Trump’s playbook. Rubio is betting that by running at Trump directly he can turn a multi-candidate race into a two-person contest, with his ever-escalating insults taking on more and more earned-media airtime to rival that of Trump.

The effort started in Thursday night’s debate, after Trump’s third-straight early-state victory, as the GOP fears about its front-runner reached new heights. The first in which Rubio appeared without the threat of establishment favorite Jeb Bush, he felt freed to finally take on his chief rival for the nomination. Rubio blasted Trump’s business record, highlighting the ongoing fraud lawsuit over his eponymous Trump University, and accusations he has hired illegal labor to construct his real estate holdings. Hours later, Rubio shifted from substantive attacks to personal ones, reading out ‘mean tweets from Donald,’ mocking the front-runner’s poor spelling.

“I will not allow the conservative movement to be taken over by a con artist of the name Donald Trump,” Rubio said Monday, attempting to brand Trump with the same sort of epithet that has defined and sunk rivals before.

And as Trump was embroiled in questions about whether he would repudiate the Klu Klux Klan, Rubio, who is Cuba-American, suggested that Trump’s vacillation raised the stakes for the campaign. “There is no place in the conservative movement for David Duke, the Ku Klux Klan or any sort of bigotry,” Rubio said. “So we have to win.”

But it remains to be seen whether Rubio’s all-in effort is too little too late, as Trump threatens to bludgeon his way to the nomination. Rubio is looking to pick up just enough delegates on “Super Tuesday” to survive until March 15, when Florida votes. The Sunshine State contest is a must-win for Rubio, though he is behind in the polls and will require a perfect storm of primary success to defeat Trump. Rubio and his aides are contemplating a convention strategy in case no candidate secures the required 1,237 delegates needed to lock in the nomination.

“I don’t care if I have to get in my pickup truck and drive around the country like I did when I ran for the Senate,” Rubio said Saturday, promising to fight on until the convention. “Donald Trump will never be the nominee of the party of Lincoln and Reagan.”

This article was originally published on Time.com.