Sen. Marco Rubio (R-Fla.), who was once called "THE REPUBLICAN SAVIOR" on the cover of Time magazine, lost big Tuesday night.

Rubio's been losing for a while. Even before Tuesday's results, Rubio had less than half of the delegates that the number-crunchers at FiveThirtyEight said he would need to be "on track" for the Republican nomination. But Tuesday night, when he lost badly in Michigan and Mississippi, made clear that he's a dead man walking.

Rubio looks likely to finish fourth in both Michigan and Mississippi, behind Donald Trump, Sen. Ted Cruz (R-Texas), and Ohio Gov. John Kasich. After Tuesday, Trump will have more than a third of the delegates he needs to secure the nomination. Unless Trump or Ted Cruz ascends directly into heaven in the next week or so, Rubio, who received more endorsements from more important party leaders than anyone remaining in the GOP presidential primary, has no realistic path to winning a majority of the delegates before the Republican national convention in July. At this point, his best hope for the presidency is a brokered convention, in which he and another loser -- probably Cruz -- have enough delegates combined to surpass Trump. Even then, Rubio would likely have fewer delegates than whoever he made the deal with, and would probably have to accept the vice-presidential spot on the ticket.

There were Republican contests Tuesday in Mississippi, Michigan, Idaho and Hawaii. In the lower 48, Rubio's defeat was total. Donald Trump won Mississippi early in the night, finishing ahead of Rubio for the 19th time in 21 tries this primary season. Trump won Michigan. Trump or Cruz will win Idaho. (Hawaii, where Rubio has his best chance of pulling out his third win of 2016, won't report votes until early Wednesday Eastern time.)

But it was the nature of Tuesday night's losses that really hurt Rubio. He won less than 10 percent of the vote in both Mississippi and Michigan, significantly less than he was showing in public polls just a few weeks ago. That suggests a collapse in his support. And in the crucial contest for delegates, he likely got shut out in the two biggest states. If early results hold, it's likely he'll receive zero of Mississippi's 40 delegates -- and zero of Michigan's 59. He's in danger of being shut out of Idaho's 32 delegates, as well. 

Rubio has long been counting on a win in his home state primary in Florida next Tuesday. But even if he wins Florida, which awards all of its delegates to the winner in the state, he'll only pick up as many delegates as he was shut out of in Mississippi and Michigan: 99.

"I believe with all my heart that the winner of the Florida primary next Tuesday will be the nominee of the Republican Party," Rubio said Tuesday night.

He may think it'll be him. But Rubio's not leading in polls of the Sunshine State.

Trump is.