It will come as no surprise to regular readers to hear that if I could design a T-shirt or bumper sticker promoting some basic political fact that is forgotten far too often, it might read: “Midterms Are For Old White Folks.” This is one way of conveying the reality that much of the alleged “back and forth” in election returns reflects the very different nature of presidential and midterm electorates, and the remarkable alignment (since 2008, anyway) of the Democratic coalition with the younger and more diverse presidential electorate, and of the Republican coalition with the older and whiter midterm electorate.

The latter alignment is the big “thumb-on-the-scale” for Republicans in 2014, and probably a bigger deal than all the issue-landscape or gerrymandering or historic “rule” advantages the GOP might have next year.

So this observation by Charlie Cook based on Greenberg Quinlan Rosner polling data draws attention to a potentially important phenomenon:

Democrats are closely watching the voting pattern of older Americans, a group that voted heavily Republican in the 2010 midterm and, to a lesser extent, in 2012; in March and July surveys, older voters’ responses are showing only about half the GOP margin they voted last November and about a quarter of the Republican margin in the 2010 midterm election. It’s unclear what exactly is going on, but this formerly strong Democratic group had moved pretty heavily against Democrats and Obama since he took office. Some signs indicate, however, this trend could be diminishing somewhat. And because older voters tend to vote in disproportionately higher numbers in midterm elections, any changes could be important.

In 2006, when Democrats made major gains, they took 49% of the senior vote. In the next mid-term, they lost seniors by a catastrophic 59-38 margin. And the Democratic share of the senior vote in the last three presidential elections has dropped from 47% in 2004 to 45% in 2008 to 44% in 2012. So it would be natural to expect a pretty bad number in this demographic for Democrats in 2014, with perhaps an even higher percentage of the electorate at play.

If, as GQR’s numbers suggest, the Republican momentum among old folks has not only diminished but reversed, that’s a very big deal.

As Cook notes, it’s not clear why this is happening if it is happening. But if Republicans are paying close attention to the phenomenon, as they should, the implications are pretty clear for those whose ideological inclinations point in this direction anyway: it’s time for another big Mediscare effort linked to attacks on Obamacare that encourage white retirees to view the Affordable Care Act as a raid on their hard-earned benefits and hard-earned earned tax dollars to show welfare on those people. Since Republicans also believe there’s big political hay to be made on Obamacare at the other end of the age spectrum, with young folks who perceive their need for health insurance as about as high a priority as their need for real estate on Mars, it’s really a no-brainer, and what “the base” would want to focus even if it didn’t represent a political opportunity.