Utah Sen. Orrin Hatch announced he will not seek re-election after serving more than 40 years in the U.S. Senate.
He said in a social media message, "after much prayer and discussion with family and friends I've decided to retire at the end of this term."
Hatch, 83, says he's always been a fighter, "but every good fighter knows when to hang up the gloves."
Hatch is the longest-serving Republican in the Senate. He chairs the powerful Senate Finance Committee and was a major force in getting a tax overhaul through in December. His retirement opens the door for Republican Mitt Romney to run for his seat.
According to the Washington Post, Hatch was under pressure from President Trump to seek re-election and block Romney for running against him.
The veteran senator was also facing harsh poll numbers in Utah, where 75 percent of voters indicated in a survey last fall that they did not want him to run again.
Hatch says he decided to retire at the end of his seventh term after "much prayer and discussion with family and friends" over the holiday break.
He says "I may be leaving the Senate, but the next chapter in my public service is just beginning."