Presidential candidate Julian Castro (D) said on Thursday evening that former Vice President Joe Biden is “wrong” to oppose decriminalizing illegal immigration.

Speaking at the League of United Latin American Citizens (LULAC) presidential forum, the former San Antonio mayor and President Barack Obama’s Housing and Urban Development (HUD) secretary was asked about the recent “friendly fire” from former Obama administration officials on the issue.

Last week, Jeh Johnson, Obama’s Homeland Security secretary, said the decriminalizing illegal immigration is “unwise” and “unworkable” and would paint Democrats as the party of “open borders.”

“I’d say Sec Johnson is wrong, VP Biden is wrong, and Congressman O’Rourke is wrong,” Castro said after making remarks about the “obviously not friendly” fire. “I will not make policy based out of political fear.”

Castro had his breakout moment at the first presidential debate when he challenged O’Rourke on eliminating Section 1325 of the U.S. immigration code, which criminalizes illegal immigration. Biden told CNN’s Chris Cuomo last Friday that he opposed decriminalizing immigration.

Castro argued at the LULAC forum that illegal immigration had been a “civil violation” and “not a criminal violation” until the post-9/11 era and Johnson’s “open borders” remark is just a “right-wing talking point.”

After accusing President Donald Trump of weaponizing immigration law, Castro said he wanted to ensure other presidents cannot use immigration law to “separate families” like the current administration.

“I will not abide by it,” Castro said. “I won’t stand for it.”