Utah Sen. Orrin G. Hatch, who had hoped to become the Republicans' fallback choice for the White House if George W. Bush stumbled, shut down his campaign yesterday and endorsed the Texas governor.

Hatch's announcement at a Capitol Hill news conference came after he finished sixth--and last--in the Iowa Republican caucuses this week. He received 1 percent of the vote and trailed even Arizona Sen. John McCain, who sidestepped Iowa for next week's primary in New Hampshire.

Hatch endorsed Bush as "the only one who can unite the party and bring back the White House to us." He had some doubts about Bush at the start but became increasingly impressed by Bush's stature as a candidate. "Now that I am out, I think Governor Bush is the only person who can get things done," including cutting taxes and improving schools, Hatch said. "I think he can reach across party lines."

Bush said he was "honored to have his support," and described the endorsement as "especially significant because [Hatch] has debated, worked and campaigned with all of us."

Hatch, 65, who is chairman of the Senate Judiciary Committee, took colleagues by surprise when he entered the crowded race last summer, noting at the time that he "believe[s] in miracles" and "it would probably take that to elect me." Asked why he was running, he joked, "Why not?"

Colleagues said they believed Hatch was running because he regarded himself as just as qualified as others, especially McCain, with whom he has had somewhat starchy relations. He saw himself, they said, as the fallback if Bush's candidacy collapsed.

But Bush's candidacy has not fallen apart, and Hatch failed to dislodge McCain as Bush's most serious rival. While Hatch was often a strong presence in debates, he trailed badly in polls and was running out of money, he conceded yesterday.

Hatch left the race in good humor, with "no regrets." He said he believed he got in too late, long after others had done so, but had hoped that his more than two decades on Capitol Hill would push him to the front of the pack. Instead, he found that people were not all that interested in his Washington experience.

While he had moved quickly from ninth to six place among GOP contenders, he joked, "some nitpickers may say" it was because of the four who proceeded him in dropping out. "Unfortunately the other candidates are not doing their part to keep this trend going."

When the huge snowstorm delayed his exit by a day, he told his wife Elaine that the storm could be a "sign from God." No, she said, "the Iowa caucuses were a sign from God."

Hatch said he plans to return to Utah on Friday, where aides said will announce his plans to seek a fifth term in November. He remains a heavy favorite to win. His likely Democratic challenger, state Attorney General Jan Graham, told the Associated Press she doubted Hatch's presidential bid would hurt him in Utah: "I think if anything people have felt a little sorry for Senator Hatch."

CAPTION: Sen. Orrin G. Hatch (R-Utah) will return to his home state Friday, where he will announce his plans to seek a fifth term in November.