Van Hilleary, a former congressman turned Capitol Hill staffer, has entered the Republican primary for Tennessee’s 6th District, which Rep. John W. Rose, his boss until very recently, is vacating to run for governor.

“We have a nation worth fighting for and I am ready to protect our shared Tennessee values in Washington D.C.,” Hilleary said on social media Friday, when he kicked off his campaign with an event in the Nashville suburb of Gallatin. 

Hilleary, who became Rose’s chief of staff in 2019, was introduced by the incumbent at Friday’s event, the Tennessee Lookout reported.

“When your chief of staff is a former congressman, he’s held in particularly high regard,” Rose said, according to the news outlet. 

A spokesman for Rose said Monday that Hilleary had resigned as chief of staff. 

Hilleary, 66, joins what’s becoming a growing GOP primary for the 6th District, which encompasses parts of Nashville and its northern suburbs and rural communities along the state’s northern border. State Rep. Johnny Garrett, Marine Corps veteran Jon Henry and Army veteran Dale Braden are, like Hilleary, closely aligning themselves with Trump. 

On the Democratic side, Navy veteran Mike Croley has announced a run, but the Republican nominee will be heavily favored in a district that Trump carried by 35 points last year, according to calculations by The Downballot. 

Hilleary was first elected to Congress during the “Republican Revolution” of 1994, which ended Democrats’ four decades of House control. 

He served four terms and mounted an unsuccessful gubernatorial bid against Democrat Phil Bredesen in 2002. He sought a political comeback in 2006, when he ran to succeed retiring Senate Majority Leader Bill Frist but placed a distant third in the GOP primary. He later worked as a lobbyist before joining Rose’s office. 

During his tenure in Congress, Hilleary, an advocate for lower taxes and smaller government, served on the Armed Services, Budget, and Education and Workforce committees. 

As a freshman lawmaker, Hilleary offered a constitutional amendment to limit congressional terms. At times, he was a thorn in the side of House GOP leaders, whom he publicly criticized as too eager to compromise. In 1997, he joined a small group of roughly two-dozen House Republicans in a short-lived effort to oust Speaker Newt Gingrich.