The Democratic Party maintained its huge edge in party identification during the month of May. Barack Obama’s Party now has the largest partisan advantage over the Republicans since Rasmussen Reports began tracking this data on a monthly basis nearly six years ago (see history from January 2004 to present).

During the month of April, 41.7% of Americans considered themselves to be Democrats. Just 31.6% said they were Republicans and 26.6% were not affiliated with either major party. This is the third straight month Obama’s team has enjoyed a double-digit edge.

Forty-seven percent (47%) of women say they’re Democrats and just under 30% identify with the GOP. Men are more evenly divided—36% say they’re Democrats and 34% Republican.

Democrats have the advantage among all age groups and also lead among those who earn less than $75,000 a year. The two parties are even among higher-income adults. Party identification is essentially even among Investors but Democrats have a 47% to 25% advantage among non-Investors.

May was also the fourth straight month that the number of Democrats topped 41%. Prior to February of this year, neither party had ever reached the 39% level of support. Rasmussen Reports tracks this information based upon telephone interviews with approximately 15,000 adults per month and has been doing so since November 2002.

These results are based upon tracking surveys of 15,000 adults per month. The margin of sampling error for the sample is less than one percentage point, with a 95% level of confidence. Please keep in mind that figures reported in this article are for all adults, not Likely Voters.

In 2004, the Democrats began the year with a 2.3 percentage point edge over the GOP. That grew to 4.0 points by March before moving in the Republican direction for the rest of the year. By Election Day in 2004, the edge for Democrats was a mere 1.6 percentage points.

In 2006, the Democrats began the year with just a 1.6 percentage point advantage. That grew to 6.1 percentage points by November.

The Rasmussen Reports daily Presidential Tracking Poll shows the race for the White House remains close. In the Electoral College, the race is a Toss-Up. Democrats continue to have a significant advantage on ten key issues tracked by Rasmussen Reports and lead on the Generic Congressional Ballot.