In his latest presidential campaign ad, Texas Rep. Ron Paul (R) positions himself as the only candidate who can stand up to the “Washington machine.”

Paul has taken hits from rivals this week for his isolationist foreign policy and hands-off approach on many issues. This ad tries to turn his longtime iconoclastic views from a negative to a positive, painting Paul as a lone man of principle in a field of compromising politicians.

In a year when every candidate wants to be an outsider, it might not be a bad strategy.

“Serial hypocrites and flip-floppers can’t clean up the mess,” the narrator says, over shots of former House speaker Newt Gingrich and former Massachusetts governor Mitt Romney . “One man stands alone ... consistent, incorruptible, guided by faith and principle — Ron Paul, the one we’ve been looking for.”

The sleek spot — Paul is making some of the best ads out there right now — comes a day after Gingrich’s past support for Romney’s Massachusetts health-care mandate surfaced.

While Paul has been in Congress since the 1970s, he can plausibly argue that he never embraced the culture. As David A. Farenthold wrote this week, Paul tends to propose bold legislation that never makes it to a floor vote, and he’s never shown interest in lobbying behind the scenes to get it there.

While Gingrich and Romney have kept their ads mostly positive, letting super PACs do the dirty work, Paul has distinguished himself with his willingness to go on the attack. It appears to be working — numerous polls show him leading in Iowa.

It’s a $600,000 buy in both Iowa and New Hampshire; Paul is spending $1.6 million on ads this week.