Rasmussen has just come out with a new poll of American adults indicating that 36 percent call themselves Republican and 34.7 percent Democrat. This is the first time in the history of Rasmussen’s polling, from 2004 to the present, that among all adults — not registered voters, not likely voters, but all adults — more consider themselves Republican than Democrat. Indeed, I believe it may be the first time in the history of major national polling that there has been such a finding.

Rasmussen writes: “In November 2008, following the presidential election, Democrats held a 7.6 percentage point advantage over the GOP. That means Republicans have picked up a net of approximately nine points over the past two years. That is a somewhat larger gain compared to the Democratic gains from the reelection of President Bush in 2004 to the Democratic takeover of Congress in 2006. However, it is similar to the gains recorded by Democrats during the four-year period from Election 2004 to Election 2008.”

That nine-point shift means that something like 25 percent of American adults changed their minds about whether to call themselves Democrat or Republican in the past two years, and a similar percentage changed from 2004 to 2008. What we have here, then, is more evidence that we are in an uncommonly fluid, even unstable, political era. Anybody who thinks it’s possible to extrapolate from these numbers where we will be in 2012 is kidding himself, save one thing: Obama and the Democrats have to do something to alter the political dynamic in their favor, because people are saying they are Republican even though they don’t like the GOP very much either.