Everybody agrees that Republicans will win the midterm elections and stand a better-than-ever chance of controlling the Senate. For months, a debate has raged over why. One analysis is structural. Democrats rely heavily on minorities and the young, who tend to skip midterm elections, making the electorate more Republican than the one that shows up at the polls every four years. Additionally, the Senate races this year force Democrats to defend far more seats, many of which are held in Republican territory.