His name is Sam Wang and he's a professor at Princeton.
Read it for yourself and enjoy!
Republicans at risk of losing the House?
...Conditions through August showed a 2% lead on the generic Congressional ballot for Democrats. As of September 20th, in the wake of the Democratic convention, the lead has widened to 4.0 +- 2.0%. Although it has yet to be appreciated by pundits, this could well translate to a November loss of the House of Representatives by Republicans
...Where things could go in the next seven weeks. Assume a +-4% opinion shift between now and November, and this leads to a popular vote prediction of D+0% to D+8% (1 sigma). This gives a Democratic takeover probability of 74%, approximately three out of four.*
H/T to Andrew Sullivan
PS: Of course, this isn't really the first such prediction: Nancy Pelosi has been making this case since last May. So I've inserted the word "academic" into the title.
Democrats recently moved ahead in the "generic" House polls. In 4 of the last 5 cycles the party leading that measure at this point in the race has ended up with the majority. There is more analysis of this at Larry Sabato's blog. However, he still considers the Republicans to be the "heavy favorites".