Gallup's generic ballot for Congress for the week of Sept. 13-19 shows a 46% Democratic and 45% Republican split in registered voters' preferences for the midterm congressional elections. It is the second week out of the last three in which the two parties have been virtually tied.
As Talking Points Memo (!) warns, Gallup's numbers have fluctuated so wildly over the last month, it's hard to put too much stock in any lone finding they publish:
Three weeks ago, Gallup reported that the GOP held a 10-point lead in congressional generic polling, marking the highest lead for the party ever registered by Gallup. A week later, the Republicans' Gallup-induced confidence dissipated, as the firm released a poll that countered the previous week's numbers. With that survey's 46%-46% tie, Democrats appeared to be right back in the game. That was until the next week's Gallup poll found Republicans back on top, 48%-43%.
In other words if you don't like what Gallup is reporting today, just wait awhile. Seriously, Gallup, nobody believes American public opinion is careening as inexplicably and unpredictably as your data suggests it has been for the past several weeks. You're losing a little credibility with this nonsense.