Brian Jack, a Trump Adviser, Will Run for Congress in Georgia

Brian Jack, a political adviser to former President Donald J. Trump, filed paperwork on Thursday to run for Congress in Georgia, aiming to replace a retiring Republican representative in a deeply conservative district.

Mr. Jack, who was the final White House political director under Mr. Trump and has remained an adviser to the former president, will run to succeed Representative Drew Ferguson in Georgia’s Third Congressional District, which includes the southern suburbs of Atlanta. Mr. Ferguson, a four-term Republican, announced his retirement late last year.

Mr. Trump gave his “complete and total” endorsement to Mr. Jack’s candidacy in a social media post on Thursday afternoon.

“I encourage Brian, a Fayette County native, to go for it, pursue his dream, and run for Congress,” Mr. Trump wrote. “He represents a new generation of leadership, and he will be a GREAT congressman.”

In a statement, Mr. Jack, who was also an adviser to Representative Kevin McCarthy when he was the speaker of the House, said that with Mr. Trump’s endorsement “comes great responsibility.” He added: “I will tirelessly work to earn the trust and support of my home district.”

The endorsement, as well as Mr. Jack’s larger relationship with Mr. Trump, will most likely give him a significant advantage in the race’s Republican primary, on May 21.

At least six other Republican candidates have entered the race, including Mike Crane and Mike Dugan, both former state senators, and Philip Singleton, a former state representative. Those candidates could draw the ire of Mr. Trump, who has a history of holding grudges and has tightened his grip over the Republican Party.

If Mr. Jack advances out of the primary, he will practically be assured a victory in the general