Republican Sen. Orrin Hatch of Utah says he will not seek re-election after serving more than 40 years in the U.S. Senate.

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.

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."

In response, the White House said President Trump is "very sad" that Hatch has decided to retire. 

Trump had been encouraging the 83-year-old senator to seek an eighth term. 

White House spokeswoman Sarah Huckabee Sanders says Trump has the "greatest and deepest respect" for Hatch and is particularly thankful for his leadership on the recently enacted tax bill.

Meanwhile, Pennsylvania Rep. Bill Shuster also announced on Tuesday that he won't for re-election. 

Shuster says he wants to focus his time and energy on working with President Trump on legislation to spend hundreds of billions of dollars to build roads, bridges and other infrastructure.

He said in a statement that he'll spend his final year in office "focusing 100 percent on working with President Trump and my Republican and Democratic colleagues in both chambers to pass a much needed infrastructure bill to rebuild America."

Shuster was bound to leave the powerful position at the end of this term anyway because of GOP rules limiting him to six years as chairman of the committee.

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