In a fight against Romney—who paid roughly 14 percent on more than $21 million in 2010 income — Democrats believe they are well placed to make the case that middle-income families have been playing by the rules and still been left behind.

“For the average family, who’s struggling right now, their income is going down,” Sen. Chuck Schumer (D-N.Y.) told CBS “This Morning” on Monday. “To at least think the system is on the level, they should be paying less than the people who make the highest income.”…

“This comes down to values,” Rep. Tammy Baldwin (D-Wis.), who has sponsored the House version of the Buffett Rule legislation and is running for Senate this year. “This isn’t class warfare.”