Jeff Roberson/AP

After a clean sweep of three states Tuesday, Rick Santorum can ride his momentum for the next three weeks.

The next big GOP primaries won't come until Feb. 28, when Arizona and Michigan take to the polls, leaving little to talk about in the way of GOP vote results, except drawn out caucuses in the small states of Maine and Wyoming.

Santorum has said he will focus his momentum on Michigan, where demographics and voting issues could supply fertile territory for his campaign themes.

The former Pennsylvania senator won the caucus states of Minnesota and Colorado on Tuesday, plus the mostly meaningless Missouri primary, where Republicans' main voting event will be caucuses on March 17. In doing so, Santorum put himself in a strong position for the dead zone of the Republican primary-the stretch between Florida's Jan. 31 vote and the Feb. 28 contests. There is a nearly month-long run featuring mainly caucus states that will not "award" delegates.

Candidates, as expected, spent less time and money on those caucus states than they did on the January primaries in South Carolina and Florida. Nevada awarded delegates based on its Feb. 4 results, but Colorado won't award any until state conventions held later. Minnesota won't award any at all.

Until Feb. 28, the only contests are in Maine and Washington-caucus states where precincts will vote over date ranges suggested by the state parties.

What's Next

Here's how the GOP voting calendar lines up in the near future. Despite Mitt Romney's losses on Tuesday, he's still facing a run of states where he performed well in 2008.

• Feb. 4 - 11 - Maine caucuses. "Vacationland" will hold its caucuses over the course of a week-but those are just the suggested dates for precincts. The state's 24 delegates won't be allocated and will be free to support any candidate at the GOP convention, giving candidates little incentive to campaign in Maine. No major polling firm has surveyed in the state recently.  2008 results: Romney 52 percent, John McCain 22 percent, Ron Paul 18 percent.
• Feb. 9 - 29 - Wyoming caucuses. Like Maine, Wyoming will let its precincts hold caucuses within a date range. The Wyoming Republican Party will announce the statewide results on Feb. 29, but they won't have anything to do with the state's 29 delegates, which will be required to state their candidate preferences before being elected Wyoming's state convention. They'll be bound to their candidate choices by word only, not by state law or party rules.  2008 results: Romney 67 percent, Fred Thompson 25 percent, Duncan Hunter eight percent.
• Feb. 28 - Arizona primary. Finally-another simple primary state. Arizona will likely draw more focus from candidates than all of the February states preceding it. Like Florida, it will award all of its 29 delegates to the statewide winner, and, like Florida, it lost half its delegates after breaking the new RNC rules prohibiting its early primary date and winner-take-all allocation scheme.  2008 results: John McCain 47 percent, Romney 35 percent, Mike Huckabee nine percent.
• Feb. 28 - Michigan primary. Another relatively simple primary state, Michigan will award its 30 delegates proportionally (based on both percent totals and congressional-district winners). Like Florida and Arizona, Michigan was penalized by the RNC.  2008 results: Romney 39 percent, McCain 30 percent, Huckabee 16 percent.
• March 3 - Washington caucuses. Much like Iowa, Maine, and Wyoming, Washington is yet another caucus state that will not award its 43 delegates to any candidate, leaving them free to support whomever they choose at the Tampa convention. 2008 results: McCain 25 percent, Huckabee 23 percent, Paul 22 percent.
• March 6 - Super Tuesday. Super Tuesday is the biggest event on the medium-term primary horizon. After Washington holds its caucuses on March 3, 10 states will vote, accounting for 437 delegates. After Super Tuesday, states making up over 35 percent of all delegates (72 percent of the delegates needed to win the nomination) will have finished voting.
• June 5 - California primary. If Republicans are still campaigning against each other in early June, Californians will cast their potentially decisive votes second-to-last; Utah will end the primary season with its June 26 contest. California will award more national delegates (169) than any other state. 2008 results: McCain 42 percent, Romney 35 percent, Huckabee 12 percent.

Santorum: On to Michigan

The former Pennsylvania senator figures to devote heavy attention to Michigan in the coming weeks.

While Romney enjoys the natural advantage of hailing from the state, where his father served as governor, and while Romney won Michigan by nine percentage points in 2008, Santorum has some cause for optimism.

Since the beginning of the campaign, Santorum's central focus has been a pitch to working-class voters in the upper Midwest and industrial rust belt-voters who've seen manufacturing jobs disappear over the last decade and a half. Santorum has repeatedly framed his economic policy as a manufacturing-first agenda. Michigan's economy, of course, is tied its manufacturing base and the automotive industry.

"We think Michigan's a great place for us to plant our flag and talk about jobs and manufacturing," Santorum said during an appearance on NBC Wednesday morning.

Delegate Math: How Long Will This Thing Take?

With no candidate approaching the number of delegates needed to win, this campaign could take a while.

Rick Santorum didn't add any delegates to his total yesterday, but ABC and other outlets have estimated how unbound delegates from Colorado and Minnesota will vote, based on the statewide results.

The current ABC News delegate estimate shows Romney (91) leading Santorum (44), Gingrich (29), and Paul (8). Jon Huntsman will get to pick two New Hampshire delegates and will presumably encourage them to support Romney, whom Huntsman endorsed upon exiting the race.

That total includes a sizable number of unbound delegates who could be swayed by rival campaigns. Few of Santorum's estimated delegates will be required to support him at the Republican National Convention, under state-party rules.

In order to win the nomination, a candidate will need the votes of 1144 delegates on the convention floor-a majority of the 2286 total Republican delegates. Technically, no candidate will be able to accrue the obligated support of enough "bound" delegates to seal the nomination before late April.

Far From Clarity

Tuesday's caucus results put a halt to the growing momentum for Mitt Romney, and, without much happening until Feb. 28, the voting calendar won't allow him much chance to further cultivate his air of inevitability.

Santorum and Newt Gingrich, meanwhile, won't have the opportunity to approach Romney in the delegate count until Super Tuesday.

The upshot: With its 397 bound delegates, and 437 delegates total, Super Tuesday may bestow some clarity on the Republican nominating picture. But with many of those delegates awarded proportionally, or doled out to winners of individual congressional districts, it's less likely that March 6 will deliver the nomination to a single candidate.

Unless one candidate picks up significant momentum in Arizona and Michigan and parlays it into a convincing, across-the-board win on March 6, the campaign will likely keep going for a while.