The GOP has lost more support among voters over 65 than any other demographic group in recent months, according to a new poll.As bad as things get for Republicans -- with women, with minorities, with youths -- there's always been one group they can count on: the old. But now one Democratic pollster sees evidence that even seniors are starting to turn on the GOP.Just 28 percent of voters 65 and older had a favorable view of the Republican Party in a national survey conducted last month by the Democratic pollster Stan Greenberg, versus 40 percent who had a positive view of the Democrats. That's a reversal from a poll Greenberg conducted in early 2011, when 43 percent of seniors saw Republicans favorably and 37 percent saw Democrats that way."It is now strikingly clear that [seniors] have turned sharply against the GOP," Erica Seifert, a senior associate at Greenberg's firm, wrote on the company's website this week. "We have seen other voters pull back from the GOP, but among no group has this shift been as sharp as it is among senior citizens."More seniors still said they plan to vote Republican than Democrat in 2014, 46 percent to 41 percent. But that 5-point margin is down from the 21-point margin seniors gave the GOP in 2010, according to exit polls. In 2012, voters 65 and over were Mitt Romney's strongest age group, favoring the GOP nominee by 12 points. (Romney outpolled his two GOP nominee predecessors, John McCain and the 2004 campaign of George W. Bush, who both won seniors by 8 points.). Among all voters, Republicans still led the generic congressional ballot in Greenberg's poll, but by a single point, 44 percent to 43 percent. The poll of 841 likely 2014 voters was conducted by cell phone and land line July 10 to 15 and carries a 3-point margin of error in either direction.The senior shift was an unexpected result that jumped out of a poll Greenberg was conducting for the Women's Voices Women Vote Action Fund focused on unmarried women's views on economic policy. Seifert believes it's largely a reaction to the Republican-backed plan by Rep. Paul Ryan to phase in changes to the Medicare system, which dates to 2011. But the slide appears to have accelerated this year: Greenberg clocked Republicans' advantage with the over-65 vote at 11 points in January, 6 in March and 5 in July. "That's the sort of shift that turns the tables," Siefert told me.. In November 2010, 49 percent of seniors said Republicans were the better party on the economy; just 34 percent said Democrats were. In the July 2013 poll, the parties were essentially tied on this metric, with 43 percent saying Democrats and 42 percent saying Republicans.Seniors' approval of the GOP-led House has dropped from 45 percent in early 2011 to 22 percent today. They have gone from identifying more as Republicans than Democrats by a 10-point margin to identifying more as Democrats than Republicans by a 6-point margin. Fifty-five percent say the GOP is too extreme, and 52 percent say it is "out of touch" and "dividing the country."Greenberg is a Democratic pollster, to be sure. But his work is widely respected on both sides of the aisle. Republican pollster Whit Ayres didn't question the idea that seniors are souring on the GOP. "I don't think any Republican pollster who's looking at the numbers is sanguine about the state of the Republican brand at this point," he said. "You are going to see the impact of the damaged brand in every demographic group."Nonetheless, Ayres noted, Greenberg's survey still has Republicans poised to win in 2014, if by a narrower margin than the 2010 wave. "What is striking to me in this survey is that the generic ballot is a dead heat," he said. "Republicans are actually one point ahead."Seifert, however, believes Republicans' advantage could erode if the party keeps up its emphasis on pure obstructionism in Washington. "We used to hear a sort of equal-opportunity anti-Washington, anti-partisan line from voters in our focus groups," she said. "Increasingly, they're shifting that blame to Republicans for just saying no and refusing to compromise."