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, Mississippi, Idaho and Hawaii, made clear that he's a dead man walking.

Rubio finished fourth in both Michigan and Mississippi, behind Donald Trump, Sen. Ted Cruz (R-Texas) and Ohio Gov. John Kasich. He was third in Idaho and Hawaii but didn't secure any delegates from those states either.

After Tuesday, Trump has more than a third of the delegates he needs to secure the nomination. Unless Trump or 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.

Rubio's defeat was total in Tuesday's Republican contests in Mississippi, Michigan, Idaho and Hawaii. Donald Trump won Mississippi early in the night, finishing ahead of Rubio for the 19th time in 21 tries this primary season. Trump also won Michigan and Hawaii. Cruz won Idaho.

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 got shut out in the two biggest states: He ended up with zero of Mississippi's 40 delegates and Michigan's 59.

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.

This post has been updated to reflect the final primary and caucus results.