The former Massachusetts governor said only he can work with Congress to keep any of that from happening.
"He's ignored them, he's attacked them, he's blamed them," Romney said about President Barack Obama and Congress. "The debt ceiling will come up again, and shutdown and default will be threatened, chilling the economy."
Romney, who has struck an increasingly bipartisan tone in recent weeks, used Friday's address to help crystalize what he says would be the real-world impact of Obama's continued inability to break the political gridlock in Washington.
Indeed, whoever is elected immediately will face the so-called "fiscal cliff" - a combination of tax increases and domestic and military spending cuts set to take effect in the new year unless Congress and the White House agree on a plan to stop it.
Romney said the choice voters face Tuesday boils down to one simple question. "Do you want more of the same or do you want real change?" he told hundreds of supporters packed into a cement-floored Wisconsin warehouse.
Romney's speech followed the Labor Department's final jobs report before the election. Released Friday, it showed that U.S. employers added 171,000 jobs in October and that hiring was stronger in September and August than first thought. The unemployment rate inched up to 7.9 percent, from 7.8 percent in September, because more people started looking for work.
The report sketched a picture of a job market that is gradually gaining momentum after nearly stalling in the spring. More jobs were created than predicted, and the higher rate means more people are returning to labor force since the government only counts people as unemployed if they are actively searching for work.
In a statement issued before arriving in Wisconsin, the home state of GOP running mate Rep. Paul Ryan, Romney said the new unemployment report was a "sad reminder that the economy is at a virtual standstill."
While polls have shown the economy is the top concern of most voters, Romney's advisers don't believe the new jobs number will have any impact on the election. They said the report was likely a wash - with a slight uptick in unemployment and stronger-than-expected job growth.
The campaign says government reports mean less to people than their own personal experiences. More than 23 million people are still without a job or looking for one.
In the speech, Romney asked people to vote for "real change" if they are "tired of being tired."
"I won't waste any time complaining about my predecessor. I won't spend my effort trying to pass partisan legislation unrelated to economic growth," he said, both of them references to Obama blaming his Republican predecessor for the state of the economy and for spending a year pushing the health care law through Congress.
"From Day One, I will go to work to help Americans get back to work," Romney said.
(Copyright 2012 by The Associated Press. All Rights Reserved.)