Republican presidential hopeful and former Massachusetts Gov. Mitt Romney celebrates winning the Michigan presidential primary with his wife, Ann Romney, left, Tuesday in Southfield, Mich.

Detroit ? Who says you can’t go home again?

Mitt Romney returned to his native state of Michigan looking for his first major Republican presidential victory, and the state welcomed him back with a convincing win. He could finally celebrate – after $17 million in TV ads in three states and embarrassing defeats in two of them.

“It’s a victory of optimism over Washington-style pessimism,” the former Massachusetts governor said in an Associated Press telephone interview from Southfield, Mich., echoing his campaign speeches and taking a poke at the four-term senator he toppled, John McCain. “Now on to South Carolina, Nevada, Florida.”

Minimizing the significance of Tuesday’s vote, McCain said he had called Romney to congratulate him “that Michigan welcomed their native son with their support.”

“Starting tomorrow, we’re going to win South Carolina, and we’re going to go on and win the nomination,” McCain declared, also in an AP interview from Charleston, S.C.

Mike Huckabee, too, already campaigning in the next primary state, predicted in Lexington, S.C., he would “put a flag in the ground here Saturday.” He also jabbed at Romney, who has poured at least $20 million of his personal fortune into his bid: “We need to prove that electing a president is not just about how much money a candidate has.”

No clear favorite

Romney’s win set the stage for a wide-open Republican showdown in South Carolina in just four days. Three GOP candidates now have won in the first four states to vote in the 2008 primary season, roiling a nomination fight that lacks a clear favorite as the race moves south for the first time.

In Michigan, McCain was hoping that independents and Democrats would join Republicans to help him repeat his 2000 triumph here. Mike Huckabee, the former Arkansas governor, trailed in third, and former Tennessee Sen. Fred Thompson is making a last stand in South Carolina.

With most Michigan precincts reporting, Romney had 39 percent of the vote, McCain had 30 percent and Huckabee 16 percent. No other Republican fared better than single digits.

Previously, Huckabee had won leadoff Iowa, and McCain had taken New Hampshire. Romney won scarcely contested Wyoming.

The sad state of Michigan’s economy topped voters’ agenda in Michigan, and Romney tapped into their anguish by promising help. In contrast, McCain said he would tell them the truth, that their jobs disappeared forever with the decline of the auto industry, which was not what they wanted to hear.

Of the three candidates competing hard here, Romney needed a Michigan victory the most to invigorate a campaign crippled by searing losses in Iowa and New Hampshire. He was the only one who watched the voting returns in Michigan; his top Michigan opponents, McCain and Huckabee, campaigned in the state earlier in the day but left by afternoon to plant themselves in next-up South Carolina.

Thompson is camping out in South Carolina looking for his first win. Rudy Giuliani is doing the same in Florida, which votes Jan. 29.

The former New York mayor got only 3 percent of the Michigan vote, trailing Thompson and Texas Rep. Ron Paul as well as the top three, and he hasn’t fared better than fourth in any of the states so far. Yet, the fractured GOP field plays into his strategy of lying in wait – and making his move – in Florida in the run-up to Feb. 5 when some two dozen states vote.

Calendar quirk

Hillary Rodham Clinton was the only top contender on the Democratic ballot Tuesday. With most precincts counted, she had 56 percent of the vote to 39 percent for uncommitted delegates to the Democratic National Convention.

Michigan doesn’t typically hold its primary until February but state party officials scheduled it earlier to try to give the state more say in picking a president. The Republican National Committee objected and cut the number of Michigan delegates to the national convention by half as punishment while the Democratic National Committee stripped the state of all 156 delegates to its national convention, including 28 superdelegates who would not have been bound by the outcome of the primary.