MITT ROMNEY HAD A light home field advantage in the Michigan primary since he grew up in Detroit and his dad was a three-term governor. But that's not why he won. Romney defeated John McCain because the economy is emerging as the overriding issue in the 2008 presidential race, and Romney's message on the subject is stronger than McCain's. And Romney is far more comfortable and persuasive in talking about the economy.

So McCain needs to make an adjustment in his campaign. His strength is still national security and the idea that he could step in as "commander in chief on day one." But he can't expect to win the Republican nomination if he treats the economic issue as a marginal concern.

There's plenty he can focus on. McCain has proposed to repeal the alternative minimum tax (AMT). He wants to make it easier for individuals and families to buy health insurance and get a $5,000 (families) or $2,500 (individuals) tax credit for doing so. And he wants to cut taxes for research and development, plus make the Bush tax cuts permanent.

But McCain has two problems in discussing economic issues. One, he keeps insisting his votes in 2001 and 2003 against Bush tax cuts were not a mistake. When he says that, it drives conservatives crazy and it's their votes he needs. Two, he now says he's for a bipartisan commission to deal with Social Security solvency. Conservatives regard the commission option as a way to force Republicans to raise taxes.

The most alarming

McCain has an opportunity now to craft a proposal to stimulate the economy and stimulate Republicans as well. Jack Kemp, the champion of supply-side tax cuts, is reported to be drafting one for McCain. Romney hasn't yet produced a stimulus package either. His economic proposals in Michigan focused on reviving the auto industry, once the state's pride and joy.

It's too bad Romney gave his victory speech just as McCain was delivering his. McCain would have benefited from hearing Romney run down a list of conservative goals he hopes to achieve as president. McCain could--and should--do the same, citing his votes for conservative judges and support for free trade, just to name two.

But McCain's loss in Michigan--a stage on which he trounced George W. Bush in 2000--is hardly fatal. Nor does victory make Romney the frontrunner. Not that he'd want to be so dubbed. Winning improves a candidate's poll numbers, but actual voters don't appear to be affected. They don't swoon. Momentum? Winning hasn't generated much of that in 2008.

This means Romney shouldn't expect a serious bump in South Carolina, which holds its primary on Saturday. In fact, he doesn't. Instead, Romney intends to concentrate on winning the Florida primary10 days later on January 29. However, if he doesn't finish in the top three in South Carolina--that's a distinct possibility--the press will surely gig him for it.