Alabama Republican Rep. Mo Brooks is backing Roy Moore in his Republican primary run-off against Sen. Luther Strange, who was endorsed by President Trump.

“I have voted for Roy Moore because Roy Moore not only stands with America, he will fight for America! I urge you to join that fight,” Brooks said at a rally Saturday, according to Roll Call. Brooks voted via absentee ballot as the run-off election is on Sept. 26. Polling has consistently put Moore, a former Alabama Supreme Court chief justice, ahead of Sen. Strange.

The Alabama GOP Senate primary is significant not only because the state hasn’t elected a Democrat to the Senate since 1992, but because Trump made the surprising decision of supporting Strange, who is backed by Senate Majority Leader Mitch McConnell and establishment forces such as the Chamber of Commerce. (RELATED: Trump Attacks McConnell Day After Claims Of Unity)

Trump tweeted Saturday night following Brooks’ endorsement that he will travel to Alabama to campaign for Strange.

“I will be in Huntsville, Alabama, on Saturday night to support Luther Strange for Senate,” Trump wrote. “‘Big Luther’ is a great guy who gets things done!”

The Daily Caller recently reported that Trump’s former chief strategist Steve Bannon privately charges that Trump’s son-in-law Jared Kushner, in an attempt to curry favor with Capitol Hill, urged the president to back Strange. A White House official told TheDC that Kushner never discussed the endorsement with the president.

Since leaving the White House, Bannon has gone to war against Strange as his outlet Breitbart prominently features negative stories about the incumbent senator.

Updated with Trump’s announcement he will travel to Alabama