Sen. Pat Toomey (R-PA) endorsed Rep. Lou Barletta (R-PA) in a video on Tuesday to challenge Sen. Bob Casey (D-PA) in the 2018 midterm election.

In a video endorsing Barletta, Sen. Toomey called Barletta a “trusted conservative and a relentless fighter for hardworking Pennsylvanians.”

“No one in the House of Representatives has been more committed to fighting to protect our borders or to ending dangerous sanctuary city policies than Lou Barletta,” Toomey declared.

“When we recently needed an ally in the House to pass the most sweeping tax reforms in a generation, Lou was there every step of the way,” Toomey argued. “It’s time we all unite behind Lou and support him with our time, our energy, and most of all, with our vote.”

Congressman Barletta announced in August that he hopes to challenge Sen. Bob Casey in the 2018 midterm election. Barletta, a staunch opponent of illegal immigration since his time as mayor of Hazelton, Pennsylvania, told Breitbart News that he wants to put “America First” and “Pennsylvania workers first.”

In an exclusive interview, Barletta told Breitbart News that if he were in the Senate, he could be “the difference, just that one vote,” to repeal Obamacare, secure America’s borders, and stop illegal immigration.

Barletta also chided Sen. Casey, whom he argued will continue to reject and obstruct President Trump’s agenda:

Here in Pennsylvania, Democrats, Republicans, and independents all voted for Donald Trump because they were rejecting the Obama policies that hurt their jobs here. I want to support the American worker, the Pennsylvania worker, and take this country in the direction that President Trump campaigned on. Bob Casey is going to resist and reject and obstruct everything President trump plans to do. I believe it’s wrong to go against the American people and the American worker, and this one vote, this one seat, could be the entire difference to putting the country in a different direction that the American people voted for.

Barletta told Breitbart News, “Our immigration should be merit-based, and we should be able to pick who is able to come into our country.”

Barletta also said he remains committed to helping President Trump build the southern border wall, end chain migration, and end the diversity visa lottery.

Politico named Rep. Barletta one of the “must-watch candidates of 2018,” and Roll Call labeled Sen. Casey one of the most vulnerable senators in the 2018 midterm elections.

Rep. Barletta said in a statement on Tuesday, “Sen. Toomey has been a leading conservative voice in the U.S. Senate, and he has a strong record of winning tough campaigns in Pennsylvania,” adding, “I am proud to have his support and friendship, and I look forward to working with him to continue fighting for Pennsylvania”: