A new poll confirms that voters don't just want their Social Security benefits protected, they want them expanded - in overwhelming numbers, across geographical distances, and crossing all party lines. It's not just "liberals" who feel that way. Three out of four Republican voters support it.

What's more, voters say they're far more likely to vote for candidates who vote to increase Social Security benefits. This is a winning issue for Democrats who are willing to take a firm stand as defenders - and expanders - of Social Security.

Overwhelming support.

Pollster Celinda Lake summarizes her findings by writing that "voters overwhelmingly support increasing Social Security benefits."

Lake and her team interviewed voters nationwide and in seven "red, blue, and purple" states, asking likely voters in November's election if they support "increasing Social Security benefits and paying for that increase by having wealthy Americans pay the same rate into Social Security as everybody else."

The response was, indeed, overwhelming:

90 percent of Democrats said they support the idea, and 75 percent strongly support it.

73 percent of independents support it; 55 percent strongly support it.

73 percent of Republicans support it; 47 percent strongly support it.

63 percent said they are more likely to vote for a member of Congress who votes to increase Social Security.

70 percent said they are less likely to vote for someone who votes to cut Social Security benefits.

These findings are consistent with earlier polling (compiled in PopulistMajority.org) which found, for example, that "87% of voters favor protecting Social Security and Medicare."

So why aren't more Democrats supporting Social Security benefit expansion?

Good policy, good politics.

To be sure, some Democrats have already signed onto the idea, including Senators Tom Harkin, Sherrod Brown, Mark Begich, and Elizabeth Warren. (We spoke with Sen. Brown about Social Security on The Zero Hour; the clip can be found here.)

Increasing Social Security benefits is certainly the right thing to do. The 2008 financial crisis eroded many Americans' retirement security, which was already being battered by corporate America's retreat from fixed-income pension plans. The bailout rescued the stock market, but not the financial security of ordinary Americans. And current Social Security payments are quite low, with the US ranking 26th out of 30 developed countries in the level of benefits provided.

(Where's that good old American exceptionalism when we need it?)

For someone like Alaska's Begich, who is up for reelection this year, Social Security expansion isn't just smart policy. It's also a very smart political move. 76 percent of voters in his notoriously Reddish state (remember half-term Governor Sarah Palin, anyone?) support the idea, while 59 percent strongly support it. 59 percent of likely Alaska voters tell pollsters that they're more likely to vote for a candidate who votes to expand the program.

Smoking out the imposters.

Those numbers, and those across the country, are extremely compelling. And there's another compelling reason for Dems to push for Social Security expansion: the Republicans have outflanked them on this issue before. Republicans ran to the left of Democrats in 2010 with a "Seniors' Bill of Rights," promising to protect Social Security and Medicare.

This was a craven move, given the fact that their party opposed both programs when they were created and had been trying to cut them for decades. But it worked. Democrats lost the House of Representatives that year.

Now Republicans are once again seeking to blur the differences between themselves and their opponents on this issue.

On the wrong side of a winning issue.

It doesn't help that Democratic leaders like President Obama, former President Clinton, and Minority Whip Steny Hoyer took their own whacks at the so-called "entitlement" piñata. Democrats like these have been steeped in the outdated, discredited, and widely unpopular economic theories of Wall Street-backed groups like "Third Way."

These Democrats' support for cutting Social Security has cost their party dearly in the polls, obscuring political differences and distancing Democrats from what may be their party's signature achievement.

It made matters worse when the President introduced the "chained CPI" cut to Social Security benefits in last year's proposed budget. It was framed as a gesture to Republicans on Capitol Hill, but we thought the Republicans would use the move to frame Democrats and not themselves as the 'anti-Social Security party.' We wondered how long it would take Republicans to use this proposal against Democrats, should the President proceed with it as planned.

We underestimated their zeal. A Republican House leader attacked the idea from the left within fifteen minutes, calling the move "a shocking betrayal of seniors."

Cotton or polyester?

This dynamic can be seen playing out in Sen. Mark Pryor's Arkansas re-election race. Republican challenger Tom Cotton has been fighting Pryor's accusations that he supports a Republican proposal which would raise the Social Security eligibility age even further and cut benefits with the same formula President Obama proposed in his 2013 budget.

Cotton has used a cacophony of messaging in response, raising everything from immigration to Obamacare. He even made a video ad with his mother, saying he will vote to "protect and preserve benefits for seniors like Mom."

That's evasive and misleading. It may even be an outright lie. (Mrs. Cotton, maybe you should wash that boy's mouth out with soap.) But it's certainly effective in blurring the distinction between Cotton and his opponent.

How to win on Social Security.

Imagine how effective it would be if Pryor, and every other Democratic candidate running this year, changed the rules of the game by endorsing a plan to expand Social Security benefits. Pryor's new ads could be a model for the nation: "Tom Cotton, will you stand with me in pledging to increase Social Security benefits?"

It would certainly shift the terms of the debate and make it easier to understand. "It's a yes or no question, Tom: Are you with us or not?"

Republicans have become shapeshifters on the issue of Social Security. Looking at poll numbers like these, it's easy to understand why. Fortunately, Democrats can easily reveal them for what they are, by backing a fair sensible policy for increasing Social Security benefits - one which can help avert a retirement crisis in this country.

These "overwhelming" poll numbers make it clear that Democrats have everything to gain if they do.