Last Updated Mar 2, 2016 4:33 AM EST
There's no question Donald Trump is a winner: After Super Tuesday, the Republican candidate has now won at least 11 GOP presidential nominating contests. He's done it with diverse coalitions of supporters in every corner of the country, from New Hampshire to Nevada and back to South Carolina, Georgia and Alaska.
Yet now that Trump appears to be the presumptive GOP nominee, his party has another question to grapple with: Is he the winner they want?
"Donald Trump will never get to 1,237 delegates," Sen. Marco Rubio of Florida declared to CBS News' Charlie Rose, seemingly suggesting the GOP establishment may even consider challenging Trump's claim to the nomination at the GOP convention in July.
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Rubio has won just one nominating contest -- the caucuses in Minnesota. Even so, he said, "I'll do anything it takes to keep Donald Trump from being our nominee. Anyone who won't condemn the KKK -- there's no place in the party for that."
In spite of Trump's dominance Tuesday night, none of the other GOP candidates is ready to cede the nomination to him. Sen. Ted Cruz of Texas pulled off a much-needed victory in his home state and potentially gained some momentum with additional wins in Oklahoma and Alaska. Ohio Gov. John Kasich -- who never expected to perform well on Super Tuesday -- exceeded expectations in Vermont. And even retired neurosurgeon Ben Carson, whose support never surpassed 10 percent on Super Tuesday, said Tuesday that he is "not ready to quit." He's staying in the race, he said, because the political system is "rotten to the core."
The closer Trump gets to the GOP nomination, the more the GOP establishment drags its heels, finally coming to grips with the controversial businessman's popularity among conservative voters.
"How could you do that, nominate somebody who's crazy? Donald Trump's just crazy," Republican Sen. Lindsey Graham of South Carolina, himself a failed 2016 candidate, said to CBS News on Tuesday night. Trump's candidacy, Graham said, "will tear the party apart -- we're going to lose to Hillary Clinton."
Graham added, "Ted Cruz is not my favorite... but we may be in a position where we have to rally around Ted Cruz as the only way to stop Donald Trump."
The senator slammed Trump for alienating Hispanic voters. Earlier in the day, House Speaker Paul Ryan, R-Wisconsin, admonished the GOP front-runner -- without explicitly naming him -- for failing to unequivocally reject bigotry. Other prominent members of the Republican Party, including moderates like Christine Todd Whitman and conservatives like Sen. Ben Sasse, have blatantly disavowed Trump. Meanwhile, a group of Republican business leaders held a conference call Tuesday to discuss ways to stop Trump's march to the nomination.
Trump, for his part, sounded like a slightly different candidate Tuesday night -- one ready to assume responsibility as the face of the Republican Party.
"I'm a unifier," he declared from his Florida resort, Mar-a-Lago. "I know people will find that hard to believe. Once we get all of this finished, I will go after one person, that's Hillary Clinton."
Trump continued, "We are going to be a much finer party, we're going to be a unified party, and we are going to be a much bigger party -- our party is expanding... I think we're going to be more inclusive, more unified, and I think we're going to be a much bigger party in November."
Indeed, exit polling shows that Trump wins the support of both men and women, as well as voters of all ages and education levels. He does well among moderates, conservatives and independents. However, it's unclear whether the GOP voters who supported Cruz and Rubio in the primary would turn out for Trump in the general election. In six of the exit polls Tuesday night (Alabama, Arkansas, Georgia, Tennessee, Texas and Virginia) voters were asked how satisfied they would be if Trump, Cruz, or Rubio won the nomination. As many as 74 percent of non-Trump voters said they would be dissatisfied if Trump were the nominee.
Unhappy GOP voters could be especially problematic in a state like Virginia -- a purple state with a diverse, dynamic electorate that will be critical in the general election. The exit polling out of Virginia perfectly illustrated the split emerging in the GOP.
Trump voters in Virginia said they are angry at the way the federal government is working, they want a temporary ban on non-citizen Muslims, and they are very worried about the direction of the economy. Trump performed most strongly among less affluent voters and those with less education.
By contrast, nearly half of Virginia voters who oppose a ban on non-citizen Muslims chose Rubio. Most voters who said they were dissatisfied but not angry with the government chose Rubio. Also, Rubio's support increased among voters with higher levels of education.
"I believe we are seeing a great political party shatter before our eyes," Wall Street Journal columnist Peggy Noonan told CBS News on Tuesday night.
This level of dissension within the Republican Party isn't completely unprecedented, Republican political consultant Rick Davis pointed out on CBSN. In 1976, Ronald Reagan challenged President Gerald Ford's claim to the GOP nomination, leaving the party with no clear nominee at the start of the party convention that year.
This year, the current delegate math suggests Cruz is best poised to challenge Trump. While Rubio insists he'll challenge Trump all the way to the convention, his performance Tuesday didn't help his cause. Rubio failed to meet the 20 percent threshold in Texas necessary to claim any of the state's 155 delegates. He also failed to meet the 20 percent threshold for delegates in Alabama and just barely crossed it in Tennessee.
The senator's poor showing on Super Tuesday makes the March 15 primary in his home state in Florida all the more critical -- especially since the delegates in Florida are awarded on a winner-take-all basis.
Trump, however, pointed out Tuesday night that he currently has a double-digit lead over Rubio in Florida. "We're going to spend so much time in Florida," the front-runner said, adding that Marco Rubio "is a lightweight, as I've said before."