During the month of April, just 32.7% of Americans identified themselves as Republicans. That's down from 34.0% in March and the weakest performance for the GOP since our monthly reports began 28 months ago in January 2004.

However, the GOP loss did not translate into gains for Democrats. Instead, the number of Americans unaffiliated with either major party increased to 30.9%, the highest total we've measured.

The number of Democrats remained steady at 36.4%. A month ago, 36.7% of Americans considered themselves Democrats.

These results come from Rasmussen Reports tracking surveys of 15,000 voters per month.

Democrats now have a net advantage of 3.7 percentage points over the GOP. That's up from 2.7 percentage points a month ago, but unchanged from a year ago.

Only once in the past 28 months have Democrats enjoyed a bigger advantage than they do today. That came in March, 2004, when 38.3% identified themselves as Democrats and 34.3% as Republicans. The closest the Republicans have come to parity was in September 2004 when 37.3% of adults said they were Republican and 37.9% said they were Democrats.

Please keep in mind that these figures are for all adults, not Likely Voters. Republicans typically do a bit better among Likely Voters.