Senate Majority Leader Harry Reid (D-Nev.) already brought up the widening gap between the rich and the poor twice this week, most recently in his Thursday Capitol Hill news conference with the Senate Democratic leadership team.
"There is no greater challenge this country has than income inequality, and we must do something about it," Reid said, pledging January passage of a $25 billion extension of the emergency unemployment benefits that expire Dec. 28 for 1.3 million people.
Reid was echoed by two of his deputies, Sens. Dick Durbin (D-Ill.) and Chuck Schumer (D-N.Y.).
Durbin borrowed the moral authority of Pope Francis for his remarks, citing the pontiff in a challenge to the Senate to raise the minimum wage when it comes back from the Christmas break.
"[Francis] warned that income inequality leads to, in his words, 'an economy of exclusion and inequality, and a globalization of indifference,'" Durbin said. "It challenges all of us, and it particularly challenges those of us who have been blessed with an opportunity to serve in public life and in the United State Senate.
"There are people who got up and went to work today, and will go to work tomorrow and work every single day, work very hard, and despite their best efforts, they're not making enough money to live to the next paycheck," Durbin added. "They're living below the level of poverty in America. That is unacceptable."
Schumer, who ran the Democratic Senatorial Campaign Committee in the successful 2006 and 2008 cycles, predicted that income inequality would be such a powerful issue in 2014 that it would trump any problems with Obamacare.
He said the first test for the GOP would come when Reid and Democrats start the push for extending jobless aid. "They should be aware the tectonic plates of our politics are changing," Schumer said.
"The decline of middle-class incomes and the difficulty in average people getting good paying jobs has overtaken the deficit as the number one problem facing our political economy today. Our Republican colleagues should take note," Schumer said.
"Issues like job creation, minimum wage, and unemployment insurance are going to weigh on the minds of voters far more than Obamacare by the time the 2014 elections roll around," he continued, suggesting it was about time for Republicans to ditch the tea party movement that swept them to power in the House three years ago. "They better smell the coffee," he said. "The world is changing. The 2010 elections don't govern any longer."
Asked later by HuffPost why he thought that, the New Yorker cast it as a simple matter of demographics and numbers.
"[Income inequality] is growing and the middle class is more frustrated with it. It's huge. It's huge," Schumer said. "It affects many more people. Seventy-five percent of all people have insurance and they're basically happy with it. When middle-class incomes decline, it affects the broad majority of Americans."
If Schumer and company are right, it would be something of a replay of 2012, when Mitt Romney and his infamous remarks on the 47 percent helped assure the reelection of President Barack Obama.
But Texas GOP Sen. John Cornyn, who ran the National Republican Senatorial Committee in 2010 and 2012, sensed a hint of desperation in the Democrats' middle-class focus.
"It's all about changing the subject, and they want to change the subject," Cornyn told HuffPost. "I understand that. But I don't think they're going to be successful because there's going to be a cascade of events over the course of the next year that I think are going to prove that this thing, this law [Obamacare], shouldn't have been passed, and it will never work. We'll find out whether they're right or I'm right, but I'm pretty confident that it'll be a pretty good year for us."
Michael McAuliff covers Congress and politics for The Huffington Post. Talk to him on Facebook.