Former President Clinton assumed the role of campaign attack dog on Monday night, telling Obama supporters at a New York City fundraiser that the election of Mitt Romney would be "calamitous for our country and the world."

"The Republican Congress and their nominee for President, Governor Romney, have adopted Europe's economic policies," Clinton said according to the pool report, appearing to take a line from the Romney campaign's critique of the current administration and throwing it back at them.

The former president characterized the economic policies of the opposing party as "crazy" and linked Republican proposals with the Euro debt crisis, saying, "Their economic policy is austerity and unemployment now, and then a long term budget that would explode the debt when the economy recovers so the interest rates would be so high, nobody would be able to do anything."

He described President Obama's economic policy as "job growth now and long-term budget restraint."

Clinton was appearing with President Obama at the house of Marc Lasry, the billionaire founder of the hedge fund Avenue Capital Group. It was the first of three fundraisers jointly attended by the two presidents, who are slated to raise at least $3.6 million dollars by the end of the night for the Obama Victory Fund, a joint fundraising committee of Obama for America, the Democratic National Committee and several state Democratic parties.

Clinton's efforts to hit the opposition come days after he praised Mitt Romney's "sterling business career" at Bain Capital, widely interpreted to be a direct affront to the Obama campaign.

"I don't think that we ought to get into the position where we say this is bad work," Clinton said of private equity in the CNN interview which aired Thursday. "This is good work."

At the fundraiser Monday evening, Clinton said President Obama "has good politics, he's got a good record, he's made the best of a very challenging situation, he deserves to be reelected."

The current president returned the compliment, saying ""Nobody has a better grasp and understanding of the issues than this man."

"When we work together, we can't be stopped," Obama said.