Washington ? In a seesaw campaign, President Bush has opened a lead over John Kerry in their drive to White House victory by making gains in the Midwest and solidifying his Southern base.

The race is spread over 19 states, with the fiercest competition in Ohio, Florida, Iowa, Minnesota, New Mexico and Pennsylvania, according to state polls and interviews with strategists in both parties.

Two months before Election Day, the president has 20 states firmly in his column and eight leaning his way, for a total of 237 electoral votes. It takes 270 to win the White House.

The Democratic challenger has 11 states plus the District of Columbia in hand, with five states leaning his way. That puts Kerry at 211 electoral votes.

Just two weeks ago, state polling was breaking toward Kerry on the heels of the Democratic convention in Boston. Surveys had shown him opening narrow leads in Florida, Michigan, New Hampshire and a few other hotly contested states. Campaign aides talked of an electoral cruise.

Expectations were raised, which is dangerous when voters are so evenly divided.

In Kerry’s case, his fortunes reversed when the Republican-leaning Swift Boat Veterans for Truth aired an ad in August accusing the Vietnam war hero of exaggerating his record.

Kerry belatedly condemned the claims, only after the campaign stir made an issue of his credibility and led to questions about his anti-war activities 33 years ago. By the time Bush’s nominating convention began in New York, Kerry had lost the advantage he had coming out of Boston a month ago.

That gave Bush a huge opportunity to put some room between him and Kerry with a convention script pitched to moderate voters and reminders at every turn of the president’s leadership after the Sept. 11 attacks. Two polls released after the convention, which ended Thursday, gave Bush a double-digit lead nationwide.

Some Democrats were demanding changes in the Kerry campaign, saying Bush was threatening to put the race away. Others urged calm, knowing it would fall on deaf ears.

“If we as a party all agree not to panic, these polls will not be enormously important,” said Jim Jordan, who faced his share of party angst as Kerry’s first campaign manager. “In the seven or eight states where this thing is going to be decided, I can promise you there are no double-digit leads.”

He appears to be right, though it will take another week to determine whether the president got a boost in the battlegrounds from the convention — in what states, and for how long.