Number of self identified Republicans on the other hand is up slightly. Unaffiliated increased by more than the Republicans.
"The number of Republicans in the country increased by a percentage point in December, while the number of Democrats fell back two points to the lowest level ever recorded by Rasmussen Reports.
During December, 35.4% of Americans considered themselves Republicans. That’s up from 34.3% in November and just below the high for the year of 35.6% reached in May.
At the same time, just 32.7% of adults said they were Democrats, down from 34.9% in November. The previous low for Democrats was 33.0% in August of this year."