Sen. Orrin Hatch of Utah, the longest-serving Senate Republican, announced Tuesday he will retire at the end of the year, rebuffing the pleas of President Donald Trump to seek an eighth term and paving the way for Mitt Romney to run for the seat.Hatch made his decision public Tuesday afternoon via a video announcement."When the president visited Utah last month, he said I was a fighter. I’ve always been a fighter. I was an amateur boxer in my youth, and I brought that fighting spirit with me to Washington," he said. "But every good fighter knows when to hang up the gloves. And for me, that time is soon approaching."Hatch, 83, was under heavy pressure from Trump to seek re-election and block Romney, who has been sharply critical of the president. But Hatch, who emerged as one of the president’s most avid loyalists in the Senate, decided to retire after discussing the matter with his family over the holidays. 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’s decision comes just weeks after Trump signed a sweeping tax overhaul into law, a measure that the senator helped write as chairman of the Finance Committee. The bill represented something of a capstone to Hatch’s four decades in Congress and Sen. Mitch McConnell, R-Ky., the majority leader, even deemed it as such last month in what was seen as a subtle effort to usher his colleague to the exits.Hatch’s decision clears the way for the political resurrection of Romney, the former Massachusetts governor and 2012 Republican presidential nominee who is now a Utah resident and is popular in the Mormon-heavy state. Romney has told associates he would likely run if Hatch retires."It would be difficult to defeat Mitt Romney if he were running here," said David Hansen, a longtime Utah Republican strategist and chairman of Hatch’s political organization.Romney intends to make his intentions known in a matter of weeks, the New York Times reports, citing an adviser who spoke on the condition of anonymity. His senior campaign team will include Matt Waldrip, who had been running Romney’s annual policy retreats, a longtime fundraiser, Spencer Zwick, and his former chief of staff, Beth Myers.Zwick did not confirm Romney would enter the race, but said "of all the people who can run, Mitt will represent and honor the legacy of Sen. Hatch more than anybody."As for fidelity to Trump, Zwick was more restrained."When there are things he agrees with him on, he’ll be a big supporter, and when there are things he disagrees with, he’ll voice that," he said.Romney was unaware of Hatch’s decision and of late had been operating under the assumption that the senator would run again, not even bringing up the possibility of a campaign while skiing Monday with friends in Utah.That is in part because Hatch had privately told Romney he was not sure he was ready to leave a seat he has held since 1977 and White House officials did all they could to nudge him into another campaign. Last month, Trump flew with Hatch on Air Force One to Utah for a day of events that was aimed entirely at lobbying the senator to run again.Trump announced he was vastly shrinking two of Utah’s sprawling national monuments, reversing decisions made by presidents Barack Obama and Bill Clinton, at the request of the senator. And the president used a speech in Salt Lake City to say that he hoped Hatch would "continue to serve your state and your country in the Senate for a very long time to come."The senator returned the favor at the White House when Trump signed the tax measure, calling him "one heck of a leader.""We are going to make this the greatest presidency we have seen, not only in generations, but maybe ever," Hatch said.The president has had Romney on his mind. Over golf, Trump asked Sen. Lindsey Graham, R-S.C., what he thought of the former Republican nominee. (Graham said he praised Romney and predicted he would be a solid senator.)Romney repeatedly assailed the president during the 2016 campaign, calling Trump "a fraud," and Trump returned the favor, stating that Romney "choked like a dog" in the 2012 race. The two had something of a rapprochement after the election when Romney was briefly considered as secretary of state, but White House advisers are uneasy about having such a well-known critic in the Senate.But as the president prodded Hatch to stay, voices in his home state were urging him to go. On Christmas Day, the Salt Lake Tribune named the senator "Utahn of the Year," but not for flattering reasons."It would be good for Utah if Hatch, having finally caught the Great White Whale of tax reform, were to call it a career. If he doesn’t, the voters should end it for him," the editorial concluded.In his retirement announcement, Hatch dwelled on his long record, which includes popular, bipartisan initiatives like the Children’s Health Insurance Program and the Americans With Disabilities Act, as well as more partisan achievements, like his prominent role in the confirmation of Supreme Court justices and his authorship of last month’s tax law, which passed without a Democratic vote."Only in a nation like ours could someone like me — the scrappy son of a simple carpenter — grow up to become a United States senator," he said, addressing Utah voters. "As your senator, I’ve always sought to fight for those who could not fight for themselves. And I believe the results speak for themselves."