NEW YORK -- Now the campaign ad crush and TV spending spree really begins in the presidential race.
The TV ad campaign, with total spending expected to swell to $1.1 billion, starts up again now that the party conventions are over and the two-month sprint to the general election is under way.
Just over one-third of that amount has been spent so far, according to the Kantar/Campaign Media Analysis Group, which tracks campaign ad spending.
That means the campaigns and independent groups will spend more on the air in the final eight weeks of the presidential contest than they did in the first five months.
The biggest change is on the Republican side, with Mitt Romney now free to tap millions in general election funds he had collected but could not spend until becoming the party's official nominee. That means the GOP's significant spending advantage over President Barack Obama and his Democratic allies will grow, making it the first time that an incumbent will have been outspent on the air.
National polls show Obama and Romney in a virtual dead heat, but only eight states are considered true battlegrounds: Colorado, Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio, and Virginia. Obama carried them all against Republican John McCain in 2008, but they are too close to call for now.
Flush with new cash, the Romney campaign poured nearly $5 million into ads in those states beginning this weekend. A series of state-specific ads hit Obama on defense spending, business regulations and housing; another ad uses President Bill Clinton's words from the 2008 primary race against Obama.
Republican-leaning independent groups led by the American Crossroads and Crossroads GPS kept Romney in the game throughout the summer while he regrouped from a tough GOP primary contest. Priorities USA Action, the only significant pro-Obama super PAC, has been far outpaced by the conservative-leaning groups.
Those and other independent groups emerged after a 2010 Supreme Court decision loosened campaign finance laws, allowing wealthy individuals to spend unlimited sums on political activity as long as they stay separate from the campaigns themselves. The Crossroads groups are backed by former President George W. Bush's longtime political counselor Karl Rove. Americans for Prosperity, another pro-Romney group, was founded by the billionaire brothers Charles and David Koch.
Together, the Crossroads groups spent about $66 million on ads through the end of August. Of that, $58 million came from Crossroads GPS, which is organized as a social welfare group under tax laws and thus does not have to disclose its donors. AFP, which also does not disclose its donors, spent $35.2 million during that time.
The Obama campaign spent $166 million on ads through Aug. 30, compared with $74 million by the Romney campaign and $22 million by the Republican National Committee. But now, with Romney's general election resources available and the Republican-leaning groups continuing to air ads, the Obama campaign seems set to be swamped on TV.
"It will be no holds barred on the Republican side. All that money the Obama campaign has been expecting Romney to spend on ads will finally start to flow," Kantar/CMAG vice president Elizabeth Wilner said. "The Obama campaign is betting on their message, while the Romney campaign is betting on tonnage."
Obama campaign officials acknowledged Friday how outmatched they are by Republicans on TV but said they had enough money to compete. They said their ability to identify voters and get them to the polls would help offset the advertising disadvantage.
Romney and the independent groups spent $245 million on ads through the end of August while Obama and his allies spent $188 million, according to information from media buyers provided to The Associated Press. Obama's team front-loaded its ad spending in the spring, but Republicans caught up in June and began outspending Obama by mid-July, often by a 2-1 margin.
Republicans abandoned their efforts in Michigan and Pennsylvania after hoping to make those Democratic-leaning states competitive for Romney.
The GOP hopeful was born in and grew up in Michigan, where his father served as a popular two-term governor. Pennsylvania has a large population of white, working-class voters, which has long been one of Obama's weakest demographic groups. A significant shift in momentum for Romney could put those and other states back in play.
Carl Forti, a top adviser to the Crossroads groups and Restore Our Future, another pro-Romney super PAC, said the battleground map "absolutely" could expand and that, if it does, the Republican-leaning groups will be eager to take advantage.
"For people who have only partially been paying attention until now, we have an opportunity to win them over," Forti said. "As long as they're disgruntled with the current president, they'll continue to look elsewhere."
Both sides are looking at Wisconsin as a potential new battleground after Romney named Wisconsin Rep. Paul Ryan as his running mate. Americans for Prosperity and Restore Our Future each spent about $2 million there earlier in the campaign after Republicans beat back a Democratic- and union-backed effort to recall GOP Gov. Scott Walker. Priorities USA Action has recently begun airing ads in Wisconsin, where polls still show Obama leading Romney.