The campaigns for Ted Cruz and John Kasich announced they are coordinating their campaigns in at least three upcoming primaries in order to hurt Donald Trump’s ability to collect delegates before the Republican National Convention. In statements released Sunday evening, the campaigns said that Kasich would pull his campaign from Indiana’s May 3 primary to give Cruz a better chance of beating Donald Trump. Likewise the Cruz campaign agreed to step back and let Kasich surge ahead in Oregon and New Mexico, which hold their primaries on May 17 and June 7, respectively. The campaigns are finally listening to Mitt Romney.

In February, the former presidential candidate argued that the campaign playbook that governed past primaries was “shredded.” He suggested candidates gang up against Trump, and for conservatives to cast strategic votes in their respective states for the best-performing candidate whose name doesn’t rhyme with “chump.” That way, delegates could choose an actual conservative at a contested convention. Currently, neither Cruz nor Kasich can collect 1,237 delegates in the 12 weeks before the convention. Their only hope is for a contested convention. Now, it might be a little too late. This strategy could have worked well in last week’s New York primary where Cruz got 15% of the vote and 0 delegates, while Kasich got four delegates to Trump’s 89 (with a couple still undecided).

Naturally, Trump is none-too pleased by the coordination, something he calls unfair. He said in a statement on his website, “It is sad that two grown politicians have to collude against one person who has only been a politician for ten months in order to try and stop that person from getting the Republican nomination.” It’s because Cruz and Kasich are seasoned politicians that they know the advantage of temporary alliances, and that “the enemy of my enemy is my friend.”