President Barack Obama faces a major political test later this year when U.S. voters go to the polls in the November midterm congressional elections. Public opinion polls and political experts suggest Republicans will make gains in November, and that would have a significant impact on how Mr. Obama is able to govern over the nexttwo years. Republicans are confident about their chances of gaining seats in the November elections. All 435 seats in the House of Representatives will be up for election, as well as more than one-third of the 100 U.S. Senate seats. Republicans need to gain 40 House seats to retake control of that chamber, which they lost in the2006 congressional elections.A Republican takeover of the House would drastically curtail President Obama's ability to get his agenda through Congress. Republicans are also likely to gain seats in the Senate this year. Democrats currently control 59 of the 100 Senate seats, but Republican gains would make it easier for the minority to block or defeat Democratic legislation, another potential setback for the president and his agenda