There was a time, after the primaries were over, but before the conventions began, when presidential candidates would actually go on vacation. They would not feel a compelling need to keep campaigning frenetically. Of course, those days—like waiting for a newspaper to land at your front door step—seem impossibly nostalgic now.

After forcing Hillary Clinton to capitulate, Barack Obama has not slowed down one bit. He had been on an economic tour to battleground states, trying to show that he's got the right financial ideas for America's future. John McCain, not slowing down either, has taken the week to predictably label Obama as a tax and spender and, in his own fit of nostalgia, to liken Obama to Jimmy Carter. Obama wasn't old enough to vote for Carter when he first ran in 1976; neither was anyone else born after November 1958. Today, it's fair to say that a sizable number of Americans know him best as the author of bestsellers.

Despite his efforts to distance himself from Hillary (not to mention the other Clinton, the one who spent eight years as president), Obama's economic plan has echoes of the 90s. He would raise taxes on upper-income earners and use the money to pay for more public "investments" like health care. He sounds a more skeptical note on trade, vowing to renegotiate Bill Clinton's much touted North American Free Trade Agreement. He has a sophisticated broadband and internet policy owing to advisers like Reed Hundt, the former F.C.C. commissioner; and lots of plans on Work/Life issues, owing to advisers like economist Karen Kornbluh. He's more into behavioral economics, reflecting the interests of Austan Goolsbee, the fellow who got in hot water over some alleged NAFTA comments.

On differences with McCain, Obama tries to paint his Republican rival as pursuing a "full-throated endorsement" of George W. Bush's policies. He points to McCain's wanting to make the Bush tax cuts permanent and adding additional tax breaks for corporations. The two may share goals on climate change and earmark reform, but otherwise the differences seem pretty stark. Remember, McCain once said that he couldn't vote for the Bush tax cuts in good conscience because they skewered benefits to the wealthy and because it was in a time of war.

From a political standpoint, I think Obama has really stepped in it with his proposal to raise the earning caps on Social Security. Right now, you pay taxes on your first $97,000 in wages. Then your obligation to FICA is finished. Obama would raise the cap, but when faced with questions about whether $97,000 is really rich, he suggested not raising it for some range above $97,000, but below some higher number, thus creating a kind of donut hole.

This really doesn't make sense economically. There's no economic rationale for taxing people at lower wages, then exempting them, and then reinstating the tax. That said, his proposal would would raise more revenue for Social Security—which is not nearly in the dire straits that Medicare will be in—in the coming decades. I think it'll allow McCain, perhaps unfairly, to label Obama as tax raiser. I'm surprised Clinton didn't make use of the issue earlier. Of course, Obama should get credit for having some ideas about putting Social Security on a more sound fiscal footing: an idea that makes infinitely more sense than the partial-privatization scheme favored by Bush and McCain.

The policies of McCain and Obama are clear. What both need to do is express, more clearly, a theory of economic growth. For Ronald Reagan, of course, tax cuts and deregulation were the engines of growth. For Bill Clinton it was about investments in education and an embrace of globalization and a reduction of the deficit. For Obama, he needs to be more clear about what he thinks drives the economy and what makes it grow. He's hinted at it here and there, but he needs more of it and less of a laundry list of programs. He's on to it with his talk about "bottom up" prosperity, but he probably needs to go further to show he's really in touch with those blue-collar workers who didn't cotton to his message earlier this year.

Still, with his economic tour, Obama's off to a good start, even if he denied himself and the rest of us a vacation from this long, long campaign.

Photo: Senator Barack Obama kicks off his general election campaign with two stops in Virginia, a Republican stronghold state that has not voted for a democratic presidential candidate since 1964. Barack Obama speaks at a health care themed campaign event in Bristol, VA. Photo by: Scout Tufankjian / Polaris.

Get a daily fix of how politicians, business leaders, and others in the news are faring with the Portfolio.com Capital Index.