Texas Rep. Henry Cueller, one of the more conservative Democrats in Congress, is getting a primary challenger who has support from the progressive group that backed New York Rep. Alexandria Ocasio-Cortez in her bid for office.

Immigration and human rights lawyer Jessica Cisneros, 26, who was an intern for Cuellar five years ago, announced her primary campaign Thursday to unseat the eight-term incumbent in Texas’ 28th District that stretches along the southern border with Mexico and reaches north into San Antonio.

In a news release Thursday, Cisneros labeled Cueller “Trump’s favorite Democrat,” highlighting his A rating from the National Rifle Association; his votes to defund sanctuary cities and women’s health facilities that provide abortions; and his relationship with the Koch brothers, the Wichita, Kansas-based energy barons that have spent millions of dollars supporting libertarian think tanks and conservative political candidates.

Cuellar, who was first elected in 2004, is a former chairman of the fiscally conservative Blue Dog Coalition. He voted with Democratic leadership 76 percent of the time in the last Congress, the third-lowest score among Democrats in President Donald Trump’s first term, according to CQ’s Party Unity Study. He also voted with Trump 67 percent of the time in the 115th Congress, the second-highest score for a House Democrat, according to CQ Vote Watch.

“South Texas votes Democrat because we believed a Democrat would protect our rights and fight for our families,” Cisneros wrote on her campaign website unveiled this week. “But Cuellar is not a Democrat. We need to elect a representative who is accountable to us — not big corporate donors, lobbyists, Trump and Republicans.”