What Each Republican Candidate Needs to Do to Win the Nomination

— -- With the last two debates in the rearview mirror and all eyes turning to pivotal matchups next Tuesday, Republican candidates are charting out their paths to clinching the GOP nomination.

But most aren’t looking all that likely.

In order to clinch the nomination, candidates need to win a majority of the available delegates from all the states -– making 1,237 delegates the magic number to win the bid outright in the GOP.

If no candidate is able to obtain more than half of the delegates, a contested convention is set into motion. Delegates are bound to vote for their candidates on the first ballot of July meetings in Cleveland, but if that vote fails to yield a nominee with more than half of all votes, most delegates will be free to vote for whomever they choose until a candidate can take home a majority.

The most plausible path for Donald Trump’s challengers would be through a contested convention, as the remaining delegates dwindle with each passing primary and caucus.

Trump has the likeliest shot of winning the nomination outright, but he still faces important contests in the weeks ahead.

Here’s an outlook of what each GOP candidate needs to do to win the nomination from here:

Donald Trump (458 delegates as of March 11)

The real estate mogul needs to win just over half of the remaining delegates (53 percent) from this point, certainly possible with upcoming winner-take-all states beginning on March 15. If Trump can defeat both Rubio and Kasich in their home states next week, it’s possible for him to clinch the nomination outright even without winning a majority of delegates after that point (48 percent). The number of delegates he has to secure gets smaller if he can also nab winner-take-all Arizona in late March. But if Trump loses both Florida and Ohio, he’ll face a tougher battle, needing six in 10 of the remaining delegates (60 percent) as Rubio and Kasich gain new momentum from their victories.

Ted Cruz (359 delegates)

The road is expected to get rockier for Cruz after Florida and Ohio, who isn’t expected to have a shot at winning either state. Right now, he needs 60 percent of the remaining delegates, but will need more than two-thirds (68 percent) of the delegates remaining if he loses Ohio and Florida -– a difficult feat without handily defeating Trump in upcoming delegate-rich states. The electoral map will also present challenges for the Texas senator: most of his friendly Southern states have already passed and upcoming Midwestern states are throwing more support behind Kasich and Rubio.

Marco Rubio (151 delegates)

The Florida senator faces a virtually impossible climb to the nomination outright, even with his home state of Florida in his pocket. Even assuming he wins Florida, he will need three-quarters (75 percent) of the remaining delegates to win the nomination -– a very unlikely task with Donald Trump just holding steady with his current 35 to 40 percent support in states that are not winner-take-all. And if Trump defeats him in Florida, Rubio would need to take home five out of every six remaining delegates (83 percent).

John Kasich (54 delegates)

Likewise, Kasich faces a virtually impossible path to the nomination outright, pinning his hopes on Cleveland. Even with a victory in Ohio on Tuesday, he’ll need 85 percent of the rest of the delegates, essentially impossible given the proportional allocation in some remaining states. If he loses, he will need to win 90 percent of the remaining delegates. Kasich has already said that his path lies in a contested convention, hoping that delegates will opt to strip their support away from Trump and Cruz.