At the end of the video, the narrator comes into focus as he says: "there's not much time left, and the future of our country is at stake." It's Clint Eastwood in the starring role backing the Republican nominee Mitt Romney.
Mr Eastwood's ad was developed by American Crossroads, a Super PAC (Political Action Committee) run by Karl Rove, the former chief strategist of President George W. Bush, whose efforts have raised $80m on behalf of Mr Romney.
In the presidential campaign so far, the total amount of money raised by the Super PACs in support of both the President and the former Massachusetts governor stands at a staggering $661m, according to their filings last week to the Federal Election Commission. Their spending – which has mostly been on television attack ads – has been recorded at $512m. But there are questions over how effective the negative ads are among voters in the swing states which have been the main targets.
John Geer, a political science professor at Vanderbilt University has teamed up with the polling institute YouGov to survey the reaction of 600 independent voters over the last few months. Describing the ads as "carpet bombing" of voters whose favourite shows and sports games are constantly interrupted, Mr Geer says that according to his project "the millions of dollars spent on advertising are not having much of an effect on the public's preferences."
However Jonathan Collegio of American Crossroads argued that the conservative Super PACs were levelling out the playing field. “Incumbents have a huge monetary advantage and Super PACs evened it out,” he said in an email. Mr Collegio added that "between May 1 and August 31 Obama outspent Romney on TV ads by $100m and the Gallup tracking poll remained tied."
Mr Rove's American Crossroads fundraising is second only to the pro-Romney Restore our Future Super PAC which has brought in $132m. In third place is the pro-Obama Priorities USA Action, founded by former Obama aides, which has raised $64m from outside groups.
Restore our Future yesterday unveiled its latest ad as it prepares to spend a total $20m in eight battleground states in a final blitz before next Tuesday's election. The ad describes the "flatlining" economy under President Obama and urges voters to "demand better" or face four more years of a "dead economy."
A major donor to Restore our Future is casino magnate Sheldon Adelson and his wife Miriam, who each contributed $5m earlier this month. Mr Adelson intends to spend more than $70m in the campaign. Other donors include wealthy Texans from the energy industry.
After initially holding back from creating Super PACs, the Democrats have spent around $400m. The pro-Obama Super PAC donors include media figures such as comedian Bill Maher.
The non-partisan Sunlight Foundation is campaigning for greater transparency from the Super PACs. The foundation's editorial director, Bill Allison, yesterday recognised that their arrival actually suited both campaigns by providing political cover for the candidates. But "we need better disclosure around some of these groups and to find out whether there is a corrupting influence," he said.
The Super PACs are a creature of a 2010 Supreme Court ruling, known as Citizens United, which lifted restrictions on campaign spending, legalising unlimited corporate donations to independent political committees.
The Supreme Court not only prompted a dismayed reaction from President Obama at the time who blasted the decision as "damaging to our democracy" by allowing "corporate and special interest takeovers of our elections." It also triggered satirical reaction, particularly in the form of a spoof by comedians Jon Stewart and Stephen Colbert which demonstrated the impossibility of maintaining a firewall between the presidential contenders and the so-called independent political committees.
In the three weeks following the Supreme Court ruling, Mr Rove's American Crossroads had registered its website. Craig Unger, the author of Boss Rove, notes that after an initial trip initial to Texas to meet with wealthy donors, American Crossroads obtained commitments of about $30m – nearly four times the amount that the Republican National Committee had in its coffers. Thanks to the Super PAC's non-profit status, it does not have to disclose the identity of its contributors.
During the campaign, the television ads have aired in the dozen battleground states – including Ohio, Florida, Virginia, Colorado, Wisconsin and Pennsylvania – which will decide the election outcome.
Although the outside contributions to the pro-Obama Super PACs have lagged behind the opposing camp, the Democrats have been able to keep pace with Romney by using campaign money to pay for TV ads at a lower rate than the Super PACs which can be charged twice or three times as much.