WASHINGTON — Barack Obama and John McCain will both pursue the image of a strong leader in troublesome economic times as they meet tonight for their third and final presidential debate.

Their faceoff comes as Obama widens his lead in typically Democratic states — poll results released Tuesday showed him with at least a nine-point lead over McCain — and campaigns with an air of optimism about his prospects, while McCain seeks a way to gain ground and finds himself defending traditionally Republican states with less than three weeks left in the race.

"We cannot spend the next four years as we have spent much of the last eight: waiting for our luck to change. ... As president I intend to act, quickly and decisively," McCain said Tuesday in battleground Pennsylvania. There, he unveiled new economic proposals and previewed a possible debate strategy: argue that he would be different from Bush and better than Obama.

One day earlier in swing state Ohio, Obama outlined his own economic plan and showed off his own pitch. He suggested that McCain was more of the same and that putting a Democrat in charge was the only way to fix the economy's woes.

Utah Gov. Jon Huntsman Jr. hit the campaign trail in New Mexico Tuesday for McCain.

Huntsman held what was billed as a victory rally for the GOP presidential candidate in Farmington, N.M. The governor was joined by local officials but not by McCain during his daylong trip paid for by the McCain campaign.

"He's been everywhere, from New Hampshire to New Mexico," said Huntsman spokeswoman Lisa Roskelley, including a recent appearance in California earlier this month alongside the party's vice-presidential nominee, Alaska Gov. Sarah Palin.

Huntsman was an early and loyal supporter of McCain, despite the popularity in Utah of his former rival for the GOP presidential nomination, Mitt Romney. It was Huntsman who formally nominated Palin at the Republican National Convention in Minnesota last month.

Roskelley said the governor is ready to do whatever he can for McCain in the remaining days before the election. Huntsman is on the Nov. 4 ballot in Utah but has maintained a strong lead in his bid for a second term.

"We've told the campaign, when he's available, he'll do it," she said. "He'll likely be doing more events."

The economic crisis has transformed the presidential campaign over the past month. Obama has built leads nationally and in key states as the turmoil has returned the nation's focus to the unpopular Bush's policies. Now, the burden is on McCain to try to reverse his slide.