The GOP needs a net gain of 39 seats in the House of Representatives to wrest control from Democrats and take the Speaker position away from Nancy Pelosi and it looks like they will do so, with other handicappers listing gains at over 40.
The GOP needs a net gain of 10 seats in the Senate, which was regarded as virtually impossible as of a year ago, even six months ago rated as highly unlikely, and now being seen a possibility.
The House projections have not changed as of the last report but the Senate projections have been raised by one seat:
Concerning the Senate, the Democrats still appear to have a small edge to maintain narrow control—but Republicans have the opportunity to run the table, win a net +10 seats, and gain a one-seat majority. For now, we are raising (by one seat) the likely Republican Senate gain, from +7-8 to +8-9. This was the level at which we had the GOP before its disaster in Delaware.
Even Democratic leaning pollster, Nate Silver at FiveThirtyEight, is that "Republicans have a 72 percent chance of taking over the House, up from 67 percent last week. Moreover, they have nearly even odds of a achieving a net gain of 50 seats; their average gain in a typical simulation run was between 47 and 48 seats."
With less than three weeks to go until the midterm elections, the GOP is very likely to be in a position to force Barack Obama to actually work with them and putting a stop to the rubber stamping of his agenda and the jamming through of his policies without regard to public opinion or bipartisanship of any kind as Nancy Pelosi and Harry Reid have done for him in the House of Representatives and the Senate.