economist.com – Nov 3rd 2014, 15:15 by M.D., D.H., P.K. & R.G. THE big prize in America’s mid-term elections, which will be held on November 4th, is control of the US Senate. The Republicans are expected to hold on to their majority in the House of Representatives without difficulty, and Barack Obama is not up for re-election, but the Senate is very much in play. Democrats currently enjoy a 55-45 majority (including two independents who vote with the party).