Bush competed in Minnesota and Pennsylvania in 2000 and 2004, only to have them tip Democrat in the closing weeks. Today, registered Democrats in Pennsylvania outnumber Republicans by nearly 1 million. But a downturn in the economy, or Romney catching fire elsewhere in the nation's economic heartland could tip both Republican.
Obama campaign aides have sent signals they will contest Arizona, arguing the Hispanic voter trend favors them. However, they and Romney aides say that tipping point is years away and that it remains a safe Republican state.
Likewise, Missouri has been decided by slim margins in the past three elections, but carried by Republicans in all three.
As in Arizona and even Georgia, where Obama's team has also made overtures, Missouri is considered GOP territory this year.
"The Romney campaign is going to make sure we have the resources to compete in states where Democrats throw a head fake," Romney's Madden said. "And I'm saying Missouri is not being targeted by the Democrats."
Associated Press writer Ken Thomas in Washington contributed to this report.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.