(CNN) -- Republicans favor former New York Mayor Rudy Giuliani for the GOP presidential nomination in 2008, while Democrats are looking toward Sen. Hillary Rodham Clinton of New York for their nominee, according to a CNN poll released Thursday.

Thirty-one percent of the 432 poll respondents who identified themselves as Republicans chose Giuliani from a list of potential 2008 nominees, according to the survey conducted by Opinion Research Corp. on behalf of CNN.

The next closest choices were Sen. John McCain of Arizona, with 20 percent, and former House Speaker Newt Gingrich, with 12 percent. (View the complete poll results for all potential GOP and Democratic candidates -- PDF)

No other Republican broke out of the single digits, and 14 percent of respondents said they were unsure about their choice.

Among the 517 identifying themselves as Democrats, 37 percent chose Clinton, and 20 percent favored former Vice President Al Gore.

The 2004 Democratic presidential nominee, Sen. John Kerry of Massachusetts, and Kerry's running mate, former Sen. John Edwards of North Carolina, trailed with 11 percent each.

All other Democrats fielded 3 percent or less in the survey, while 8 percent of the respondents said they were unsure about their choice.

Asked if they would only vote for a candidate who opposed the Iraq war at its inception in 2003, 56 percent of Democrats said no, and 41 percent said yes.

In a separate survey conducted of 1,004 adult Americans, 86 percent said they favor Congress passing legislation that would raise the minimum wage.

The surveys were conducted by telephone August 30 to September 2.

The overall margin of error was plus or minus 5 percentage points, except for the minimum wage question, where the margin of error was plus or minus 3 percentage points.