The former Massachusetts governor harshly criticized Republican candidates such as Ohio Gov. John Kasich and Texas Sen. Ted Cruz for not stopping Trump in the primary. The two largely avoided attacking Trump for much of their campaigns.

“Ted Cruz was basically praising Donald Trump through the whole process,” Romney told CNN’s Wolf Blitzer, who was hosting the discussion. As for Kasich, “he was in well after the time there was no possible pathway to becoming the nominee.”

Romney was warmly received by many of his allies, earning a lengthy round of applause when he wondered aloud about the future of the GOP: “Seeing this is breaking my heart.” The 2012 nominee was visibly emotional and appeared to tear up in making the remark.

But Romney was also challenged by some questioners who were trying to whip up support for Trump. Romney has pledged to never support Trump, and many of his fund-raisers feel similarly.