It's already over for Rubio

The landscape is unrelentingly bleak for Rubio. He is even at risk of being knocked out of the race by Kasich. If Kasich beats or stays close to him in the establishment-friendly states voting before March 15, Kasich could gain momentum and overtake Trump in Ohio. If Rubio is unable to close Trump’s 18-point lead in Florida, Kasich might emerge as Trump’s only marginally viable rival after March 15.

In desperation, GOP elites and mega-donors are finally coalescing behind Rubio. No doubt, Kasich would enjoy the irony if he were to outlast their anointed candidate. That alone might be reason enough for him to stay in the race.

The leadership of the GOP has three choices now. They can pull out the stops to deny Trump the nomination, one way or another. Senate Majority Leader Mitch McConnell, among others, is already exploring these options. If they attempt and fail, they will shatter the party. If they succeed, Trump is likely to retaliate by making an independent bid for the White House, virtually ensuring a massive defeat for the GOP in November, including loss of the Senate and perhaps even their House majority.

Or the institutional GOP can cede the nomination to Trump, distance itself from him, and free down-ballot candidates to run against him or with him as they choose. In practice, if Trump is the nominee, many GOP candidates are likely to take this course whatever the national party decides. In fact, this is already underway. This strategy might save some incumbents but at what cost to the GOP as a functioning political party?