Emphasizing a major Democratic theme for the 2014 election season, Minnesota Sen. Amy Klobuchar released a report on income inequality Thursday that showed the top one percent of American households made, on average, 22.5 times more than the average annual income of all U.S. households in 2012.

Klobuchar used the report, prepared for her as vice chair of the U.S. Congress Joint Econmic Committee, to endorse legislation to raise the federal minimum wage to $10.10 per hour. Klobuchar said the increase would raise 4.6 million Americans out of poverty.

Minnesota is also considering raising its minimum wage.

The gap between the country's richest citizens and its middle class stands to be a near-constant Democratic refrain in the run-up to the mid-term elections. Klobuchar pointed out that the number of American households meeting the economic definition of middle class shrank friom 48.7 percent in 1980 to 41.1 percent in 2010.

"Income inequality is a direct threat to the American promise that with hard work and determination everyone has the same fair shot at building a better life for their families," Klobuchar said in a news release that echoed a familiar Democratic talking point.