The number of Democrats in the nation increased by more than half a percentage point to 39.4% in May. The number of Republicans remained unchanged from a month ago at 32.6%. The number not affiliated with either major party fell to 28.0%.

Since last August, the number of Democrats nationwide has ranged from 38.7% to 41.6%. The number of Republicans has stayed in a narrower range from 32.6% to 33.8% (see history from January 2004 to present).

One year ago, in May of 2008, the number of Democrats peaked at 41.7% as the competition between Barack Obama and Hillary Clinton for the presidential nomination generated enthusiasm for the party. At that time, Democrats enjoyed a double-digit lead over the GOP in terms of partisan identification.

The Democrats now enjoy a 6.8-percentage-point advantage over Republicans. During the first three months of 2009, the Democrats averaged a seven-point advantage.

Despite this month’s gains, the number of Democrats stayed below 40% for the third straight month. Prior to that, the number of Democrats had topped 40% for six straight months and 11 out of the last 14.

While the partisan identification numbers shift little from month-to-month, the numbers document just how dramatically the political environment has changed over the past four years. In January 2005, as President Bush was inaugurated for his second term in office, the Democrats enjoyed just a one-percentage-point advantage over the GOP.

Rasmussen Reports tracks this information based upon telephone interviews with approximately 15,000 adults per month and has been doing so since November 2002. The margin of sampling error for the full sample is less than one percentage point, with a 95% level of confidence.
Keep in mind that figures reported in this article are for all adults, not Likely Voters. Republicans are a bit more likely to participate in elections than Democrats.

Data from our monthly partisan identification survey is used to set weighting targets for other Rasmussen Reports surveys. The targets are based upon results from the previous three months.

The Rasmussen Reports daily Presidential Approval Index shows that President Obama continues to earn favorable reviews early in his administration.

Democrats have a modest advantage on 10 key issues tracked by Rasmussen Reports and on the Generic Congressional Ballot.