A new set of Quinnipiac University polls taken for The Wall Street Journal and the Web site of The Washington Post make it pretty clear why John McCain has more or less given up in Michigan, and that he is struggling in three other battlegrounds: Wisconsin, Colorado and Minnesota.

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The surveys come as McCain, who has taken to calling himself the underdog in the presidential race, also trails Obama by anywhere from 4-10 percentage points nationally. (Track Polls)

A month ago McCain trailed Barack Obama by only 4 points, 48-to-44, in Michigan. Now it's nowhere near that close. The latest numbers from Michigan show Obama up 54 percent to 38 percent and poised to keep the 17 electoral votes John Kerry won in 2004.

The new poll was conducted before McCain announced he was pulling staff and advertising out of traditionally Democratic Michigan, ceding the state to Obama. (Read Story)

And since the two began debating head-to-head, Obama's lead has grown substantially bigger in Wisconsin, too. Last month, Obama led McCain 51-43 percent. Now, Obama leads 54-37 percent. His 17-point lead is the largest any poll has shown for him in the state.

Particularly troubling for McCain is that Obama leads among independent voters, who were expected to determine the outcome of the race in this hotly contested state, 52 percent to 36 percent.

The flailing national economy is also benefiting Obama with 55 percent of those polled saying it is the biggest issue in the race. And, a majority says Obama is better able to deal with it by 53-32 percent.

Colorado was the only state in the polls where the numbers for both candidates didn't move after the debates. Obama led McCain there 52-43 percent before and after the last debate.

However, there were positive signals for Obama, especially the fact that Obama now has a comfortable 11-point lead among independent voters, the largest bloc of Coloradans.

A majority of both male and female voters in Colorado said Alaska Gov. Sarah Palin, McCain's running mate, is unqualified to be vice president, with 52 percent of women doubting her qualifications and 51 percent of the men.

In Minnesota, which most pundits have labeled as a purple state that might move into the red Republican column this year, Obama leads McCain 51-40 percent; before the last debate the margin favored Obama 51-43 percent.

Last month's Quinnipiac poll had the race in Minnesota within the margin of sampling error. Obama is the clear favorite of Minnesota women, but he and McCain evenly split the male vote. While a solid majority of Minnesota voters say Democratic vice presidential nominee Joe Biden is qualified to be president, most voters don't see Palin in the top role.

Obama's surge could be helping down the ballot as Democratic Senate challenger Al Franken has knotted his race with Republican Sen. Norm Coleman, who led in previous Quinnipiac polls.