… It should come as no surprise that lower-income voters are reliably Democratic. However, Democrats need to do more than just “win” these voter; they need to carry them by a significant margin in order to succeed at the ballot box.
In the 2006 wave election that swept Democrats into the majority in the House and Senate, Democrats had a 22 point advantage among the 40 percent of the electorate that made less than $50,000/year.
Fast forward to 2010, when another electoral wave washed the Democrats out of power and put the GOP in charge of the House, and you see that the Democratic margin among those making less than $50,000/year had been slashed in half to just 11 points. CONT.
Amy Walter, Cook Political Report