Three-term Republican Rep. Joe Heck has filed paperwork to run for retiring Democrat Harry Reid's U.S. Senate seat.
Heck registered Monday in Las Vegas. The doctor and one-star general announced last July that he would seek the seat, after popular Republican Gov. Brian Sandoval said he wouldn't be running.
Heck's main opponent is Democratic former Nevada Attorney General Catherine Cortez Masto, who wants to be the nation's first Latina senator and keep the seat in Democratic hands.
Heck's campaign has tried to capitalize on conservative distaste for the polarizing Reid by emphasizing that the longtime Senate Democratic leader supports Cortez Masto.
Cortez Masto's campaign has sought to tie Heck to Republican presidential frontrunner Donald Trump. Heck says he's focused on his own campaign message but will support the Republican nominee.