In the battleground states considered up-for-grabs, polls show Romney has narrowed Obama's lead or caught the president.
The Obama campaign conceded he had a bad night in the first debate and promised a more aggressive approach in New York. A third and final debate focusing on foreign policy will take place October 22 in Florida.
Polls show voters consider the economy to be the most important election issue.
Unemployment fell below 8% in September for the first time since the month Obama took office in 2009. However, continuing high unemployment and slow growth have made the president vulnerable.
Romney and his campaign have sought to frame the election as a referendum on Obama's presidency, citing joblessness, slow recovery from the recession and chronic federal deficits and debt as reasons to deny a second term.
For their part, Obama and Democrats have tried to make the election about competing visions for the future. They argue Republican proposals to repeal major legislation, such as health care and Wall Street reforms, while cutting government and expanding tax cuts without identifying additional revenue sources would stall a sluggish but steady recovery.