The presidential campaigns locked horns on Tuesday over the competitive status of key battleground states that will determine who has the more likely path to victory through the Electoral College.

The Romney campaign, which has been playing political offense in recent days, claims to have momentum in states where President Obama was previously considered to have a lock on victory.

On Tuesday, the Romney campaign circulated a memo from political director Rich Beeson saying that both Minnesota and Pennsylvania were trending toward the GOP challenger.

“Not only has Minnesota been moved to 'Lean Dem' and the Obama Campaign is up in that state with a significant television buy, but the Chicago gurus have heeded Governor [Ed] Rendell’s plea and are buying television in Pennsylvania and sending the Vice-President in to help prop up their flagging campaign,” the memo read in part. 

“With one week to go, and 96% of the vote on the table on Election Day in Pennsylvania, this expansion of the electoral map demonstrates that Governor Romney’s momentum has jumped containment from the usual target states and has spread to deeper blue states that Chicago never anticipated defending.”

Recent polls in Pennsylvania show Obama maintaining a steady lead in the state. He is up by 4.7 percent over Romney, according to the RealClearPolitics average of polls.

But Republicans have also seized on a Minneapolis Star Tribune survey from last week showing Romney within 3 points of Obama in Minnesota, which hasn’t gone Republican in a presidential election since 1972.

On Tuesday, GOP vice presidential candidate Rep. Paul RyanPaul Davis RyanDischarge petition efforts intensify as leadership seeks unity Republicans fear retribution for joining immigration revolt Immigration petition hits 204 as new Republican signs on MORE (R-Wis.) will hold a press availability at the Minneapolis airport on his way to a rally in Wisconsin. 

The Obama campaign has dispatched former President Clinton to shore up support there.

Both campaigns have shifted some small-dollar ad buys to the state. 

While election analysts believe it's unlikely Obama will lose the state this year, some view the tightening race there as a sign that the president is bleeding support across-the-board, making his thin swing-state advantage over Romney all the more tenuous.

But the Obama campaign views Romney’s claims of an expanding map differently. It says the Romney campaign was posturing and “desperately looking” for a new path to 270 electoral votes.

Obama campaign manager Jim Messina sent out a statement — headlined “Romney’s desperate play” — in response to the Romney memo.

“Three things are now absolutely clear in this race — we have a significant early vote advantage in states from North Carolina to Nevada, there is no Romney momentum in the battleground states, and the Romney campaign has found itself with a tremendously narrow and improbable path to 270 electoral votes,” Messina wrote. 

“Now, like Republicans did in 2008, they are throwing money at states where they never built an organization and have been losing for two years. Let’s be very clear, the Romney campaign and its allies decision to go up with advertising in Michigan, Pennsylvania and Minnesota is a decision made out of weakness, not strength.”

The pro-Romney super-PAC Restore Our Future has launched a $2.2 million ad campaign in Michigan, although the candidate's own campaign has yet to purchase air time there. 

“The President is leading or tied in every battleground state across the country, and he leads early voting in every state across the country,” Messina continued. “Governor Romney has not been able to put away a single battleground state — in fact, as polls in the past day have showed the candidates tied in North Carolina, Republicans have raced to increase their television advertising there. Voters who haven’t heard from the Romney campaign in two years will see this desperation for what it is.”