Politico' s Shane Goldmacher reports that Florida senator Marco Rubio's path to winning the 1,237 delegates necessary to secure the presidential nomination before the GOP convention has vanished. That's correct. But that's also true for Ted Cruz. And it may soon be true for Donald Trump as well.

I asked the Cook Political Report's Dave Wasserman if Cruz has a path to 1,237 delegates in the primary season if Cruz loses Florida and Ohio on March 15 and does okay in Missouri and Illinois that same day. "No way. Cruz's best states have already voted, and he's at only 61 percent of what he needs so far to be on pace for 1,237," Wasserman replied.

But here's something important to keep in mind: Donald Trump will almost certainly be in the same position as Cruz and Rubio if he loses Ohio and Florida on March 15. He won't be able to get to 1,237 delegates in the primary season unless wins almost every remaining winner-take-all state and does very well in remaining states that award delegates proportionally.

Even though Rubio is in third place in the delegate hunt right now, he still has a realistic path to winning more delegates than any other GOP contender before the convention.

To get to first place, Rubio would first need to win the winner-take-all contest of Florida on March 15. That's obviously not an easy task as recent polls have shown Rubio trailing Trump from anywhere between 7 and 20 points. But it's not impossible. In 2012, Mitt Romney trailed Newt Gingrich by 9 points in Florida a week before the primary. But with an onslaught of TV ads and a strong debate performance, Romney won the state by 14.5 points.

If Rubio pulls off a win in Florida, he has a realistic path to first place. One scenario would involve Rubio winning the winner-take-all states of Wisconsin on April 5, Indiana* on May 3, and Nebraska on May 10. Then on June 7, the last day of the primaries, he'd need to take the winner-take-all states of Montana and South Dakota and win the vast majority of delegates in California, which awards almost all delegates on a winner-take-all basis in each congressional district. (This is just one scenario that allows for Trump racking up wins in a number of states, but I won't take the reader any deeper into the weeds for now.)

These victories would likely put Rubio in first place heading into the GOP convention, but he still wouldn't have the majority of delegates needed to secure the nomination. And a plurality would not guarantee Rubio the right to the nomination, just as a plurality wouldn't guarantee Donald Trump or Ted Cruz the right to the nomination. If Trump and Cruz delegates join forces to nominate Trump or Cruz, that's within the rights of the majority.

Donald Trump has the clearest path to winning the nomination outright during the primary season, but his path to winning 1,237 delegates would become extremely difficult if he loses both Ohio and Florida on March 15. Even a split decision on March 15 would make Trump's path to the nomination difficult. Victory in both states would put Trump in a strong position, but there would still be several plausible scenarios in which he fails to win a majority of delegates in the primary season.

It all depends on whether voters rally behind him or resist him until June 7.

*Indiana is actually a hybrid system that awards delegates both by statewide and congressional district vote on a winner-take-all basis.