WASHINGTON, Oct. 31 (UPI) -- The money continues to flow in the most expensive U.S. presidential race ever with the campaigns buying $40 million in ads for the last week, observers say.
A source monitoring ad spending told CNN that President Obama's campaign spent $22.6 million on TV commercials to run from last Monday through next Tuesday's election. Mitt Romney's campaign spent $17.4 million.
Most of the spending is going to a handful of states that are still in play. About half the money will be spent in Florida, Ohio and Virginia.
Two Republican Super PACs are also spending heavily in the waning days of the campaign, targeting states where the Romney campaign is not spending a lot of money like Michigan. That forces the Democrats to match them.
Neither candidate has received federal matching funds and don't have to observe the spending limits that go with it. With the money flowing in because of the U.S. Supreme Court's Citizens United decision, the total for the 2012 presidential race is expected to be $1 billion.
"They don't have to make as many tough, triage decisions," another source tracking ad spending said. "They have more money to spend, so they can play in more places."