DETROIT — And then there were four.
In the first post-Super Tuesday face off for the Republican presidential candidates, front-runner Donald Trump will join Ted Cruz, Marco Rubio and John Kasich on the emptiest stage yet for a GOP debate.
Ben Carson's announced departure on Thursday from the race means the quartet of remaining Republicans on the debate stage Thursday night get more time for attacks as Donald Trump treads a path to the GOP nomination and his three rivals try to trip him up. Cheered on by many Republican leaders, Ted Cruz, Marco Rubio and John Kasich are racing the primary clock to March 15, likely their last chance to stop Trump in a series of winner-take-all contests.
Trump emerged from March 1 stronger than ever in his fight for the White House, raking in seven victories and cushioning his delegate count. Thursday's debate comes just days before Michigan's primary election and roughly two weeks before key primary races in Ohio and Florida.
Rubio and Kasich have been campaigning in Michigan already this week. Trump is scheduled to hold a rally Friday.
The prime-time event will air beginning 9 p.m. on FOX News Channel from Detroit's iconic Fox Theater.
It comes amid a growing anti-Trump movement among Republicans, including 2012 GOP candidate, Mitt Romney, who called Trump a phony and fraud on Thursday, saying the businessman-turned-candidate is "playing the American public for suckers."
Trumpeting the anti-Trump message
He might be the indisputable front-runner, but the GOP is revolting rather than rallying around Donald Trump, and is now taking on his candidacy for the first time in a coordinated, albeit last-ditch, effort.
Trump's wobbling over whether to disavow the support of former Ku Klux Klan leader David Duke finally gave the Republican leaders of Congress a way to go after the billionaire publicly — without uttering Trump's name. Trump responded by saying House Speaker Paul Ryan would have to get along with a President Trump or pay some sort of "big price."
On the eve of the debate, Ryan's office confirmed that Trump's campaign had contacted the speaker's staff in a first sign of outreach. Notably, Trump has started talking about unifying the GOP. Look for Trump to be asked about the existential rift in the party and how he expects to govern.
Can Rubio out-Trump Trump? Should he?
The Florida senator who once insisted on staying above the scuffling has leapt right into it, emulating Trump's schoolyard-taunting style.
At campaign events in the past week, Rubio made sometimes crude jokes about everything from Trump's tan to the size of his hands — he even suggested that the billionaire wet his pants at the last debate. Look for whether a newly confident Rubio, emboldened by his first primary win in Minnesota Tuesday, keeps it up or takes a more statesmanlike approach.
And what to expect from Trump?
"I can't act overly presidential because I'm going to have people attacking from every side. A very good man, Ben Carson's not there anymore, so now we're going to have more time for the fighting," he said.
Thanks to Rubio's win Tuesday, Cruz can no longer say he's the only Republican who has shown he can beat Trump. But he won three states on Super Tuesday — Alaska, Oklahoma and his home state of Texas.
And the delegate math shows that Cruz is emerging as the candidate who might stop Trump. Look for some confidence from Cruz, because on Super Tuesday alone he came close to Trump. For the night, Trump won at least 237 delegates and Cruz won at least 209. Rubio was a distant third with at least 94.
Even Sen. Lindsey Graham, who a week earlier joked at a dinner about killing Cruz, acknowledged on CBS that the Texas senator might be the party's best hope to beat Trump.
John Kasich, he's still in it
The debate setting is likely most helpful to Ohio Gov. John Kasich, who is looking for a strong showing in Michigan in the state's March 8 contest, to survive.
With Ben Carson not attending, Kasich will be the sole Republican candidate on the debate stage to not have a single victory in the GOP primary. He finished second to Trump in New Hampshire and Vermont.
FOX and Frenemies
Trump has uttered barely a peep about the fact that Fox News Channel is hosting the debate, and that his sometime-nemesis Megyn Kelly, is one of the moderators.
This is a marked change from the upheaval that led to Trump boycotting Fox's debate just before the leadoff Iowa caucuses. Trump had demanded that Kelly be removed; Fox refused and Trump headed a few miles away to host his own event.
He later said that could have been one of the reasons he lost Iowa to Cruz.
Trump has not tweeted about Kelly in weeks. In an interview with the Associated Press this week, Kelly said she thinks Trump has more confidence now.
"He knows he can handle me. He can handle any interviewer," she said.
The Associated Press contributed to this report.