MILWAUKEE - Wisconsin Democrats went on the attack against Mitt Romney on Monday ahead of the Republican presidential contender's first visit to the state since August -- an appearance Romney canceled "out of sensitivity" for those hit by Hurricane Sandy.

"The Romney campaign is desperately spinning a narrative of 'momentum,' " Tripp Wellde, President Obama's Wisconsin campaign director, wrote in a memo. "The reality is straightforward. The makeup of this year's electorate in Wisconsin, the turnout machine built by [the Obama campaign] over the last 500-plus days and the president's consistent lead in public polling gives the president a clear advantage."

Romney had planned to visit the Milwaukee suburbs at a time when polls show him closing the gap with Obama, who won the traditionally Democratic state by 14 percentage points in 2008. A Rasmussen Reports study published Friday showed the contest tied, and other polls have put Romney within their margins of error.

"The Obama campaign is living in a fantasy world if they think they have gained any momentum in Wisconsin in the last four years," said Romney spokesman Ben Sparks. "The president obviously can't ignore Wisconsin any longer, which is why we've seen the Obama campaign send the cavalry in as a last, desperate effort to halt Romney's momentum."

But Democrats, who spent years building a stout grassroots operation here, characterized Romney's focus on Wisconsin as a last-ditch effort to win.

"They've looked at the Electoral College math, they've realized Ohio is so difficult right now and they've got to come up with a Plan B," Milwaukee Mayor Tom Barrett, a Democrat, told The Washington Examiner. "Everybody's putting a premium on Wisconsin right now."

Romney's visit was to come one day after Denver Mayor Michael Hancock warned fellow Democrats in Wisconsin that Obama was in danger of losing the state if his base did not accelerate its early-voting effort, a key component of Obama's re-election strategy.

"If the election was held today, President Barack Obama would lose the state of Wisconsin because where his base is, we have not turned out the vote early," Hancock said. "The suburbs and rural parts of Wisconsin -- the Republican base -- are voting. President Obama's base has yet to go vote."

Hancock later said he anticipates an Obama win but wanted to rally the president's supporters.

Romney wasn't the only presidential candidate to cancel a visit here. Obama was scheduled to travel to Wisconsin on Tuesday, but the White House scrapped that trip so Obama could monitor the response to Hurricane Sandy.

Democrats billed Obama's appearance in Green Bay as an opportunity for him to "solidify" his support in the state, especially in the battleground Fox Valley region. Obama won Brown County, which includes Green Bay, by a 10-point margin in 2008, but Republican George W. Bush won it by the same margin in 2004.

University of Wisconsin-Green Bay political scientist Scott Furlong, who called the region "the swing area within the swing state," said Romney may have a chance in northeast Wisconsin.

"It wouldn't surprise me if Romney won Brown County," Furlong said. "Whether he or Obama can win that total area between Green Bay and Oshkosh would be a little more difficult. They may end up splitting the whole difference along the I-41 corridor."