WASHINGTON • The Democrats are likely to lose 47 seats and control of the House of Representatives in November's elections, a top political analyst says in a new forecast Thursday.

Larry Sabato, a political scientist at the University of Virginia, also says that the Democrats are likely to lose eight or nine seats in the Senate, eight governors' offices and 300 to 500 seats in state legislatures.

"The numbers are eye-catching. Republicans are dramatically gaining in all categories," Sabato said in an interview. "It's generated by a rotten economy and a strong conservative reaction against President Obama."

The analysis marks the first time this year that Sabato and the University's Center for Politics have predicted a Republican takeover of the House.

Sabato is one of the most consistently accurate election prognosticators. His final pre-election analysis in 2006 got the exact number of Democratic gains in the House and Senate and was off by only one in governors' races. In 2008, he missed the final Electoral College count by only one, and missed the final House tally by only five seats.

"2010 was always going to be a Republican year, in the midterm tradition. It has simply been a matter of degree," Sabato said in a written analysis released Thursday.

"Had Democratic hopes on economic revitalization materialized, it is easy to see how the party could have used its superior financial resources, combined with the tendency of Republicans in some districts and states to nominate ideological fringe candidates, to keep losses to the low 30s in the House and a handful in the Senate."

With Labor Day looming, Sabato wrote, it's now clear that the summer didn't turn out as Democrats wanted.

"Conditions have deteriorated badly for Democrats over the summer. The economy appears rotten, with little chance of a substantial comeback by Nov. 2. Unemployment is very high, income growth sluggish and public confidence quite low. The Democrats' self-proclaimed 'Recovery Summer' has become a term of derision, and to most voters — fair or not — it seems that President Obama has over-promised and under-delivered."

Democrats now control the House by 255-178, with two vacancies, one previously held by each major party.

A switch of 47 seats would put the Republicans in charge by at least 226-209, assuming the two vacant seats remain in the same partisan control.

Sabato's new forecast also envisions larger losses in the Senate: eight or nine, up from the seven seats he previously predicted. Republicans must gain 10 Senate seats to take control there, however.

Democrats now control the Senate by 57-41, with two independents joining them when voting for Senate leadership and rules. Losing nine seats would leave the Democrats with 48 seats plus the two independents.