Sam Wang at the Princeton Election Consortium  is the first I’ve seen to even discuss the possibility, and he’s not an unbiased source. But he’s got data to back it up.
Using all polls and median-based statistics to address issues of outlier data  gives the median of D+4.0% that I gave. That translates to a narrow 16-seat Democratic majority in an election held today. This would be an unusual outcome. It would involve a Democratic net pickup of over 30 seats, much more than the typical gain for a re-elected president’s party. But 2010 was also an exceptional wave year  for the Republicans. Again, think of the pendulum. In any event, this is what the numbers are currently telling us.
You should review his data sets, polling numbers, and analysis before jumping in — but then you may feel like jumping off a cliff.
Look, I hold no brief for the current batch of House Republicans, including the sainted Paul Ryan. I believe they are hypocritical, hyper-partisan, and unrealistic. No more self-congratulatory group of people ever existed that had less to congratulate themselves on. I mean, voting to repeal Obamacare thirty times? Was that necessary? Meanwhile, a small task like adopting the recommended reforms to save the Postal Service billions of taxpayer dollars languished in the in-box because closing a post office in Pipsqueak, Georgia, might have offended its total population of three.
But, friends, if you think the House Republicans are shallow and ideological, allow me to introduce you to some of the prospective committee chairmen of the House Democrats. For Foreign Affairs, there’s Howard Berman, who wants war with Iran, and the quicker the better. For Natural Resources, Ed Markey. For Energy and Commerce, Henry Waxman. For Education and the Workforce, George Miller. For Judiciary, John Conyers. And for Ways and Means, Sandy Levin (who, while liberal, is at least sane compared to the deposed Pete Stark).
These old warhorses — average age, 73 — embody the calcification of liberalism in America. Obama can be as centrist and pragmatic as some think he has been, but these are the ideologues who will write the laws, and with a Democratic Senate, might even pass a few. This is scary.