Julián Castro made a big showing at tonight’s Democratic debate, and in a subsequent interview on MSNBC he elaborated his criticisms of his fellow Texan on immigration.

Castro called out Beto O’Rourke during the debate for not supporting his proposal that would decriminalize border crossings and told him at one point he would get it if he’d done his homework.

In his interview tonight with Chris Matthews after the debate, Castro knocked O’Rourke again with that line and said while he respects him, the only way to end family separation is repealing Section 1325 and treating border crossings as civil violations.

“Was he not telling the truth tonight?” Matthews asked.

“I think he was just misinformed,” Castro said. “He probably hadn’t done his homework… He was suggesting you needed to keep that law because we needed to be able to punish people who are drug trafficking or human trafficking. I agree we need to be able to punish them, but you know what, we already have laws that do that, and that’s what Congressman Ryan pointed out as well. I was happy to hear Congressman Ryan, Senator Warren, Senator Booker, and Governor Inslee have supported my position. I do find it somewhat ironic that a senator from Massachusetts and a senator from New Jersey and a congressman from Ohio have a better understanding of immigration law than Congressman O’Rourke.”

You can watch above, via MSNBC.