From CNN's article on the Republicans' growing anxiety about their prospects in November:
Most of the party's top strategists expect significant losses in House and Senate races, with some predicting Democrats could cross the 60-seat mark in the Senate.
The current balance of power in the House is 235 Democrats and 199 Republicans, with one vacant seat last held by a Democrat. The current balance of power in the Senate is 49 Democrats, 49 Republicans and two independents who caucus with the Democrats (which gives Democrats 51 votes, and control of the Senate).
CNN spoke or communicated through email Friday with six leading GOP strategists, and the consensus heading into the final week was that Republicans would lose at least two dozen House seats, perhaps more. They also predicted the party would lose at least six Senate seats, and perhaps as many as nine.
See a slideshow about the increasingly gloomy prospects for the GOP across the board.