The New York Times even gets in on the obvious:

Lost in all of the attention paid to the heavy spending by Republican-oriented independent groups in this year’s midterm elections is that Democratic candidates have generally wielded a significant head-to-head financial advantage over their Republican opponents in individual competitive races.

Even with a recent surge in fund-raising for Republican candidates, Democratic candidates have outraised their opponents over all by more than 30 percent in the 109 House races The New York Times has identified as in play. And Democratic candidates have significantly outspent their Republican counterparts over the last few months in those contests, $119 million to $79 million….