President Bush's post-convention bounce in state and national polls has left Democratic challenger John F. Kerry with a smaller battlefield upon which to contest the presidential election and a potentially more difficult route to an electoral college victory than his advisers envisioned a few months ago.

The Kerry campaign and Democratic Party officials face difficult choices in the coming days involving the allocation of millions of dollars of television ads and the concentration of campaign workers as they decide whether to concede some states to Bush that they earlier hoped to turn into battlegrounds. Bush may have to do the same but on a more limited scale.

The presidential race looks closer in many battleground states than some national polls suggest, a morale boost for Democrats after Kerry's worst month of the general election. But as the number of truly competitive states has shrunk, Kerry is faced with the reality that he must pick off one of two big battlegrounds Bush won four years ago -- Florida or Ohio -- or capture virtually every other state still available. To do that, he must hold onto several states Al Gore won in 2000 that are now highly competitive.

The Massachusetts senator spent much of the summer trying to expand the number of battleground states with television advertising and campaign trips to places such as Arizona, Colorado, Louisiana and Virginia. But in the past week, Kerry dramatically scaled back the number of states in which he is running ads. Democratic strategists privately acknowledge that only a significant change in the overall race will put some of the states Kerry sought to make competitive back into play. Democratic hopes for victory in Missouri have diminished sharply, as well.

Tad Devine, a senior Kerry-Edwards strategist, said the shift in advertising dollars marked a decision to ensure that Kerry can campaign fully in all of the truly competitive states in the final weeks. "We did not want to be in the situation that the Democratic nominee was in four years ago of having to choose between Ohio and Florida," he said. "That choice will not have to be made this time. We have the resources to compete in those states and many, many more."

Matthew Dowd, chief strategist for the Bush-Cheney campaign, called the shift by Kerry an acknowledgement that the Democratic ticket's earlier goal of expanding the electoral map had failed. "They've basically decided they're competing in 14 states and sort of ceded, for all intents and purposes, states they were in at the beginning of the year and spent a lot of money in," he said.

For much of the year, the campaigns have described the presidential race as largely confined to 20 or 21 states, which is where Bush and Kerry were running television ads and campaigning personally. But since Labor Day, the Kerry campaign and the Democratic National Committee have scaled back to 16 states total, with several considered long shots within Democratic circles.

"There's nothing particularly surprising in the provisional choices they've made," said Jim Jordan, a former Kerry campaign manager now working for America Coming Together, an independent Democratic group. "Some of these states, whatever all of our hopes were several months ago, are just hard for the Democrats at the presidential level."

An examination of state polls and interviews with strategists in the two campaigns and the parties suggests that, with less than two months before the election, the 10 most competitive states are, in order of electoral vote strength, Florida, Pennsylvania, Ohio, Minnesota, Wisconsin, Iowa, Nevada, New Mexico, West Virginia and New Hampshire.

Eleven states are the remaining battlegrounds from earlier in the year. Of those, seven lean toward Bush: Arizona, Arkansas, Colorado, Louisiana, Missouri, North Carolina and Virginia. Four tilt toward Kerry: Maine, Michigan, Oregon and Washington.

It takes 270 electoral votes to win the election, and four years ago Bush captured 271 to Gore's 266. Because of reapportionment, Bush's states are now worth 278 electoral votes, while Gore's are worth 260.

The two campaigns already have conceded between them a total of 30 states. If Bush's base states are combined with the battlegrounds leaning toward him, he starts with 217 electoral votes. Kerry's base and leaners total 207. The challenge for both candidates is finding the best combination of the remaining states. The 10 states considered the most competitive account for 114 electoral votes. To win, Kerry would need 63 of the 114. His advisers say that despite their problems, they like their chances.

The fastest route is to win the biggest states: Florida (27 electoral votes), Pennsylvania (21) and Ohio (20). Bush won two of them in 2000 -- Florida only after a 36-day recount and a Supreme Court decision that effectively gave him the state and the presidency -- and both sides believe that whoever claims two of those three this year will win the election.

Bush may face his biggest challenge defending Ohio. A Gallup Poll for USA Today and CNN released last week offered contradictory evidence on the race there. Among likely voters, Bush led Kerry 52 percent to 43 percent, but among registered voters, the race was a statistical tie, with Bush at 47 percent to Kerry's 46 percent.

Kerry strategists see Ohio as ripe for Democrats because the state lost more than 200,000 manufacturing jobs in the past four years. But Bush has drawn enthusiastic crowds in rural areas, where he performed well in 2000 and will have to again to carry the state.

"Four years ago, there was a debate in the Gore campaign about whether to even compete in Florida," Devine said. At this time in 2000, "Gore had 20 paid staffers in Florida. Today, there are 20 offices opened across the state."

But Kerry has troubles in states that Gore won. Pennsylvania appears more competitive than it was four years ago. Wisconsin, with 10 electoral votes, was one of the closest states in 2000 and remains a problem for Kerry, with Democrats worried about his soft support in the Milwaukee area and among Roman Catholics.

Kerry strategists believe they can take back New Hampshire (four electoral votes), but West Virginia and Nevada (five electoral votes each) remain challenges.

There are several unpredictable factors. One is whether Bush's convention bounce proves any more durable than Kerry's. Strategists are betting Bush will lose some of what he gained -- some polls already show that happening -- but that he will have a lead at the edge of the margin of error nonetheless. Another factor is outside events, which have played a significant role in this election and up to now have generally worked against the president.

The third factor is a state that surprises everyone. Four years ago, few thought Bush could win West Virginia until the end of the election, and its five electoral votes proved decisive. (In 1996, only President Bill Clinton among his advisers thought he had a chance of winning Florida, but he did.)

Among the other considerations they will be making in the coming weeks, strategists on both sides will have to take some gambles. Kerry, for example, still has his eye on North Carolina, the home state of his running mate, John Edwards. The Bush team sees the upper Midwest as fertile territory and will run hard at traditionally Democratic Minnesota, as well as Iowa and Wisconsin.

The campaigns know that big events such as the debates and what happens in Iraq will influence the outcome on Nov. 2, but so will the choices Bush and Kerry make in coming weeks as they piece together their electoral map strategies.

President Bush delights a crowd in West Virginia, which could shape up as a critical win in the electoral college. He carried the state in 2000.Sen. John F. Kerry greets supporters along the trail in Ohio, where he is focusing on the jobs outlook in a state that has a large manufacturing sector.