Sam Brownback lives closer to Iowa than any of the other Republicans likely to run for president in 2008. Brownback, the senior senator from Kansas, resides in Topeka, which is but a few hours by car from Iowa. And he plans to travel there quite a lot over the next 12 months--through January 21, 2008, the day Iowa Republicans plan to declare their presidential preferences.

Three weeks ago Brownback set up a presidential exploratory committee. That allows him to raise money and gauge support for a presidential race without actually announcing his candidacy. Brownback may decide not to run. But it would be unusual for someone to go so far as to establish an exploratory committee--John McCain has one and so does Rudy Giuliani--and then back out. (Evan Bayh is the exception to this rule.) Rob Wasinger, Brownback's former chief of staff and now his campaign manager, says Brownback will make a formal announcement within the next two months.

Brownback has been doing what likely presidential candidates do at this point in the preparing-to-run process. He's been working on campaign themes and their presentation, and also supervising production of a forthcoming autobiography designed to introduce him to a skeptical nation and a dismissive punditry.

A member of the House in 1995-96 and a senator since then, Brownback, who just turned 50, has polled between 0 and 3 percent in recent surveys of Republicans asked whom they'd vote for in a hypothetical GOP presidential primary. Two or 3 percent, however, is good enough for fifth

Though the dates may move up by a week or two, Iowa will be the first state on the schedule of primaries and caucuses by which the GOP will choose its presidential nominee. New Hampshire will be a week later, and South Carolina a few days after that. As currently scheduled, these early contests will be immediately followed by Super Tuesday, when GOP voters in at least 10 states will choose their candidate. Brownback would probably not be on the verge of running for president if Iowa, with its peculiar caucus process, were not first on the nominating schedule.

The way the GOP caucuses work is this: Participants in a given precinct meet on a Monday night. If the past is any guide, more than 100,000 Republicans will show up for the roughly 1,800 precinct meetings across the state. These caucuses can last for hours, as participants state and defend their candidate preferences before voting, after which the results are phoned in to party headquarters. Caucus-goers like to be personally wooed by the candidates, and the process of wooing takes place in the small-group meetings held with candidates in the months beforehand.

Iowa is a state where huge media buys, which Brownback couldn't afford anyway, may not help a candidate that much. "You can't just walk in hoping to win by spending money on radio and television ads," says Kevin McLaughlin, a Des Moines stockbroker, president of Iowans for Discounted Taxes, and now a member of Brownback's exploratory committee. On the other hand, a candidate who does well in small groups can be formidable. And Brownback's backers declare that their man is especially good in that setting. "He wears well with people," says Chuck Hurley, a lawyer and former Iowa state legislator who is also a member of the exploratory committee. "He's optimistic, he's aspirational, he's comfortable in his own skin. The more people he meets, the more people there will be who say, 'I am really impressed.'"