The United States Capitol dome, (L)currently under scaffolding for upcoming repairs, and Senate chamber (R) are seen on election day in Washington November 4, 2014. Republicans are poised to make major gains and possibly recapture control of the U.S. Senate on Tuesday in midterm elections that could serve as a public referendum on President Barack Obama's job performance. Millions of Americans will cast ballots to elect 36 senators, 36 governors and all 435 members of the House of Representatives in campaigns influenced by Obama's low job approval rating, partisan gridlock in Washington and a U.S. economy that is not growing widely enough to help many in the middle class. REUTERS/Gary Cameron (UNITED STATES - Tags: POLITICS ELECTIONS CITYSCAPE)