Obama Super PAC expands advertising to Nevada

(CBS News) A super PAC aiding President Obama is expanding its ad campaign into Nevada as part of a new approach to electoral-vote strategy.

The group, Priorities USA Action, is expanding a $30 million television advertising project that focuses on how proposals offered by GOP nominee Mitt Romney and his running mate, Wisconsin Rep. Paul Ryan, would affect the middle class. The addition of Nevada will put the group on air in Colorado, Florida, Iowa, Ohio, Wisconsin and Virginia, said Bill Burton, the group's senior strategist and a former Obama administration official. He would not say exactly how much more money the group would be spending.

At the same time, Priorities will be decreasing but not ending its presence in Florida and Wisconsin. Obama has a stable lead in Wisconsin, while polls show a very close race in Florida.

The expansion into Nevada - a substantially cheaper state to advertise in than Florida -- will bolster the number of states that could be firewalls for Obama in his quest for 270 electoral votes. For now, the ads are all in English, though the group conducted a $4 million Spanish-language campaign with the Service Employees International Union in June.

"We are focused like a laser on the math to 270 electoral votes, and that is reflected in how we're spending the new resources we have raised," Burton said.

Despite being consistently outraised by Republican groups, Priorities USA had its strongest fundraising month yet in August, when it brought in $10 million. A few days later, billionaire George Soros announced he would commit an additional $1 million to the group.