President Obama has endorsed freshman Rep. Marc VeaseyMarc Allison VeaseyArmed Services chair: US should be 'alert' about Russian mercenaries in Syria Overnight Defense: Mattis vows Dreamers in military won't be deported | Pentagon unsure if military parade will be in Washington | Dem bill would block funds for parade Dems introduce bills to block funds for Trump's proposed parade MORE (D-Texas), giving him a boost against his primary challenger on Tuesday. 

"I'm proud to endorse Congressman Marc Veasey in his re-election bid," Obama said in a statement released by Veasey's campaign Friday afternoon. "Marc is a champion for working and middle-class families in the Texas 33rd Congressional District and has quickly established himself as a leader in the fight to fix our broken immigration system. In Washington, Marc continues to aggressively defend voting rights, an issue he's fought for since his days in the Texas Legislature."

The African-American Veasey is facing self-funding Hispanic businessman Tom Sanchez (D) in the race. Tuesday's primary might be a close one, say observers, though Veasey is thought to have the edge.

The district is heavily Hispanic but has a large population of African-Americans as well — about 40 percent of its adult citizen population is Hispanic, with about a quarter of it African-American, meaning any successful candidate in a Democratic primary will need overwhelming support from one group and some crossover support as well.

Obama's endorsement touts two issues important in the heavily minority district: immigration for Hispanics, and voting rights for African-Americans.

Veasey won the newly drawn Dallas-area seat with a 53 percent to 47 percent primary win against a Hispanic former lawmaker two years ago.

Sanchez's campaign fired back.

"Marc Veasey's plea for help has been perfunctorily answered," said Sanchez spokeswoman Betsy Lopez-Wagner. "Had Veasey felt this much urgency when it came to deportations and jobs, he'd leave the president alone on the Friday before an election."

This post was updated at 3:55 p.m.