NEW YORK — Former president Bill Clinton warned that a Mitt Romney presidency would be “calamitous” for America and the world, going further than even President Barack Obama in depicting the consequences of a return to Republican rule of the White House.

 

With Obama standing to one side, Clinton slammed the Republican presidential candidate by name.

 

Clinton said Obama has earned a second term because of his steering of the economy through a “miserable situation” and “the alternative would be, in my opinion, calamitous for our country and the world.”

 

Clinton and Obama were focusing their message late Monday on economic opportunity.

Polls show that economic trends are likely to determine the election, a development that could help Romney if the economy sags significantly. Obama and Romney were tied at 46 percent in Gallup polling last week of national election preferences.

 

Clinton’s take came as he helped raise at least $3.6 million for Obama at three New York fundraisers. The two have patched over a personal rift from the 2008 campaign when Obama defeated Hillary Rodham Clinton in a bitter Democratic primary. But Clinton caused some heartburn in Obama’s campaign last week by remarking that Romney had a “sterling” business record — an assertion that undercut Democrats’ criticism of Romney’s decisions at the private equity firm Bain Capital.

 

For his part, Obama said the economy had been difficult for so many voters that some could reach the point that “you’re willing to try just about anything, even if you’ve seen it before.”

 

Clinton also said at the fundraiser that Republicans and Romney have adopted Europe’s economic policies. — AP