As a new Republican majority prepares to take control of the House, a new Republican plurality has broadened its advantage since the midterms.  In their monthly survey on party affiliation in the general population, Rasmussen shows Republicans with more than a three-point lead over Democrats.  The percentage of Republicans has hit a six-year high, while Democrats have plunged to an eight-year low:

The number of American adults calling themselves Republicans in December increased by one percentage point fromNovember to 37.0%.

Also in December, the number calling themselves Democrats fell by a point to 33.7%.

Those figures reflect the largest number of Republicans in the nation since December 2004 and the lowest number of Democrats ever recorded in tracking since November 2002.

It’s the second straight month that Rasmussen Reports polling has found more people identifying as Republicans than Democrats. Prior to November, that had never happened before.

Alternate headline: Media pollsters hardest hit. How will those pollsters whose results rely on double-digit Democratic advantages in sampling cope with the reality of a Republican plurality?  The most likely answer is that they’ll either ignore it entirely, or begin to withhold sample data from their reports on the results.

The question will really be how long it will last.  If Republicans deliver on their promises to cut spending and hold the line on taxes, that plurality may remain past the normal post-electoral period after a big win.  Note that the last trough for the Democrats was after the 2002 midterms, when George Bush defied expectations and extended his Congressional majorities, and the most recent low point for Republicans came just after the 2008 presidential election.  The peaks and valleys don’t last long, and the bigger question will be whether those voters remain patient enough for Republicans to fulfill their promises through what will necessarily be an incremental process, with the Democrats still in control of the White House and Senate.

On the other hand, it may be more to the point to ask whether Democrats have learned a lesson and can retool to compete with the GOP.  Thus far, their post-midterm performance suggests that the Democratic party leadership is still in denial over the historic rebuke voters delivered in November.  Republicans benefited from Democratic cluelessness two months ago, and perhaps it will take another electoral beating for Democrats to stop blaming the voters and rethink their agenda and tactics.  It took Republicans two cycles to figure it out, too.