The upcoming fight on the presidential campaign trail

WASHINGTON — Where to now?

With the coast-to-coast frenzy of Tuesday's voting behind them, the candidates can look forward to a comparatively relaxed primary and caucus schedule between now and the next big round of nominating contests, March 4, when voters in Ohio, Rhode Island, Texas and Vermont go to the polls.

The remaining major contenders face different calculations on spending, travel and advertising as they try to assemble enough delegates to win their party's nomination.

The Republican battlefield includes more states with winner-take-all contests, which tends to encourage a quicker resolution of its nominating battle.

But the Democrats have a dizzying array of delegate rules, so their party's candidates face a complex game board that could result in a protracted fight, beginning Saturday with a primary in Louisiana and caucuses in Nebraska and Washington. Residents of the District of Columbia, Maryland and Virginia vote next Tuesday.

Neither of the two Democratic candidates, Sens. Hillary Rodham Clinton of New York, and Barack Obama of Illinois, is expected to land a knockout punch in a single state or on a single day in the coming weeks because the loser stands to walk away with a significant share of the delegates at stake. So it becomes to some extent a game of money, momentum and perception, party analysts said.

"One candidate or the other will try to show sustained momentum," said Tad Devine, an expert on Democratic nominating rules. "Someone will try to sweep the mid-Atlantic states Feb. 12 and then pick up Wisconsin a week later. If someone sweeps those states, that's one thing. But if they split, it continues the pendulum swing and Ohio-Texas becomes essentially a showdown day."

Obama's advisers said he is well-positioned to do well in the District of Columbia, Maryland and Virginia. A recent poll gives him a double-digit lead in Maryland. Virginia's Democratic primary rules allow independents to cast ballots, which could work in Obama's favor, and Washington, D.C., has a black majority.

Michael Cryor, chairman of the Maryland Democratic Party, noted that Clinton has the endorsements of many party leaders, including Gov. Martin O'Malley and Sen. Barbara Mikulski. Obama, however, could run strongly in Baltimore, the Washington suburbs and many rural areas.

Voters in Wisconsin, with 74 Democratic delegates, go to the polls Feb. 19, the same day the party holds caucuses in Hawaii, where Obama grew up. Wisconsin has proved pivotal in past Democratic primary battles, and Obama has assigned several top ground operatives to Wisconsin, aides said.

Then, for the first time since the Iowa caucuses, there is a two-week gap before the next primaries, the March 4 confrontation in Ohio, Rhode Island, Texas and Vermont. A total of 370 delegates is at stake on what will be the most important remaining day on the primary calendar.

Polls show Clinton leading in Ohio, and she enjoys the support of Gov. Ted Strickland and many other top party leaders. But Obama is gaining strength, and he might benefit from a flood of new voters. Both candidates have held rallies in Ohio and are laying plans for a critical contest there.

"Gov. Strickland is popular, and I'm sure he'll bring some ground troops out for her," said Robert Bennett, chairman of the Ohio Republican Party who is watching the Democratic contest with considerable interest. "But what I'm seeing around the state is the Barack phenomenon attracting a lot of young voters."

"There has been heavy, heavy new-voter registration, thousands of new voters."

The economy is the chief issue in Texas, said Boyd Richie, the state's Democratic Party chairman. Richie said he and other Texas Democrats wanted to join the Super Tuesday primary parade but were blocked by state Republicans.

"As it turned out, providence may have smiled on us," he said, because Texas will now have a consequential Democratic primary for the first time in decades.

The last big Democratic prizes are in Pennsylvania, whose 151 delegates will be selected April 22, and in Indiana and North Carolina, with a combined 157 delegates, on May 6.

G. Terry Madonna, a political scientist at Franklin & Marshall College in Lancaster, Pa., said that with the exceptions of Wyoming and Mississippi, there are no contests between the March 4 votes in Ohio, Rhode Island, Texas and Vermont, and the April 22 Pennsylvania primary.

"If they're still competing after Ohio and Texas, there's this huge gap," Madonna said. "It's just a weird calendar."