Click here to watch "Bush-McCain Challenge."

Who's taken a stronger stance on assault weapons, President Bush or John McCain? Which one said U.S. troops would be greeted as liberators in Iraq? Was it both?

These are questions MoveOn.org Political Action is asking voters in its new "Bush-McCain Challenge" ad campaign, the group's latest effort to tie the presumptive Republican nominee to his party's unpopular president. The push includes a new TV spot (subscription) launched yesterday, an online trivia game and more than 300 events across the country, all intended to draw parallels between the two Republicans' track records.

The music chosen for the ad -- the theme song of the 1960s "Patty Duke Show" -- makes sport of similar statements made by McCain and Bush, including downplaying the troubled economy. "They laugh alike, they walk alike, at times they even talk alike," goes the jingle, as viewers are directed to take MoveOn's online quiz comparing their policy positions. Between shots of the pair dancing and joking onstage, the ad includes footage from Bush's official endorsement of McCain at the White House in March.

The group's campaign is capitalizing on McCain's first public appearance with Bush since the endorsement, at a campaign stop held yesterday in Phoenix. Though the event was brief -- they were together in front of the cameras for less than a minute -- the two have been participating in private fundraisers throughout Arizona. But McCain has made an effort in recent speeches to counter claims that he will merely continue Bush's legacy, putting daylight between himself and the president on issues such as global warming and foreign policy.