(CNN) - Call it the tale of two contests. While Barack Obama is making a modest rise and John McCain slightly dropping in the national polls, it's just the opposite in some states.
An update of the CNN Electoral Map Friday suggests a tightening in the race for electoral votes in the crucial battleground states. CNN is moving Missouri, and its 11 electoral votes, from "toss up" to "lean McCain," and is moving Wisconsin, which has 10 electoral votes at stake, from "lean Obama" to "toss up."
"One reason for the switch in Missouri is the latest polls in that state. The CNN/Time/Opinion Research Corporation poll indicated a five-point advantage for John McCain in the Show-Me State, and a recent ARG poll indicated the same margin," said CNN Polling Director Keating Holland. "In Wisconsin, our poll and a Big Ten Battleground poll both showed a statistical dead heat - one of the key factors prompting a switch in that state."
"Historically, state polls have often been leading indicators of national trends," noted CNN Senior Political Researcher Alan Silverleib. "Voters in tightly contested states like Missouri and Wisconsin are being inundated with the campaigns' latest television ads right now. National polls are predominatly made up of respondents from big states like New York, California and Texas where the campaigns are running no advertising at all."
CNN now estimates that if the presidential election were held today, Barack Obama would capture 223 electoral votes, to McCain's 200, leaving 115 electoral votes would still be up for grabs. The 23 electoral-vote-lead for Obama is down from a 44-point estimated lead he held in CNN's previous electoral map. Both men are well short of the 270 electoral votes needed to win the White House.
The closer race in the states comes as Obama is now up 3 points in the latest CNN poll of polls, which is an average of the most recent national surveys. Last week McCain held a small advantage. But while national polls are important, the fight for presidency is a battle for the states, and their electoral votes.
CNN is also moving Oregon, and its 7 electoral votes, from lean Obama to safe Obama. The moving of Oregon does not affect the electoral count.
"The latest polls in Oregon indicate a 10-point lead for Obama," noted Holland. "Oregon hasn't voted for the GOP candidate since 1984, and neither campaign seems to be investing much time or money in the state. That, coupled with the latest survey results, helped move the state into the 'safe' column for Obama."
The CNN Electoral Map is based on analysis from the CNN Political Unit and takes into account a number of factors, including polling, state voting trends, ad spending patterns, candidate visits, and guidance from the campaigns, parties, and political strategists. The list will be updated regularly as the campaign plays out over the remaining seven weeks.