Marco Rubio—who began taunting Donald Trump for his “tiny hands” in the days leading up to Super Tuesday—said on MSNBC Wednesday that he wish he hadn’t stooped so low.

“In terms of things that have to do with personal stuff, yeah, at the end of the day, it’s not something I’m entirely proud of,” Rubio said in a town hall. “My kids were embarrassed by it, and if I had to do it again, I wouldn’t.” But the candidate, who has less than a third of Trump’s delegates despite widespread support in the Republican establishment, said he wasn’t sorry for calling Trump’s integrity into question.

Rubio had spent the week leading up to Super Tuesday practicing his zingers at stump speeches, making fun of Trump’s spray tan and hair, as well as his hands. The insults between the candidates reached full volume at the Republican debate last week, when Trump said that his hands—and “something else”—had no size problems.

But the new tactic seemed to do little to buoy Rubio’s campaign. After a spate of disappointing finishes, some reports even say that Rubio’s campaign is fighting internally over whether to drop out of the race before his home state primary, where Rubio has long promised to win. A Florida CNN/ORC poll released on Wednesday shows Trump beating the Florida senator by a double-digit margin.