At least some of the delegates who were pledged to support Marco Rubio for president will be allowed to vote for whomever they want at the Republican Party’s convention this summer.

NBC News reached out to different state parties and found that 34 of Rubio’s 172 delegates, from Louisiana, Minnesota and Oklahoma, will no longer support him even at the convention’s first ballot, because the senator dropped out of the nominating contest last month.

Rubio ended his presidential campaign after losing his home state of Florida to businessman Donald Trump. But he has asked party leaders in 21 states and territories to nevertheless instruct the 172 delegates he had accumulated to continue to support him.

With Trump expected to fall just short of the 1,237-delegate majority needed to win the nomination outright, Rubio’s 172 could prove crucial in blocking the property tycoon who many in the party fear would lead Republicans to a crushing defeat in November.

Defectors

It looks like the other 138 delegates would still have to vote for Rubio on the convention’s first ballot. But, like many others, they could switch afterwards.

If indeed Trump falls short, the vast majority of delegates would become instantly unbound, meaning they could vote for someone else.

The campaign of Ted Cruz, Trump’s closest rival, is hard at work getting its supporters elected as delegates at state conventions so they could switch to him on the second ballot.