By renewing the totality of U.S. House seats, a third of U.S. Senate seats and a number of Governors and state assembly seats, midterm elections have long been considered a referendum on the President, even though this particular vote obeys a number of other considerations. Midterms are generally bad for the party of the President, especially when they take place during the President’s second term. They do indeed introduce a risk of institutional paralysis, which some in the country of checks and balances may consider a good thing.

Larry J. Sabato, Professor of Politics at the University of Virginia, provides us with solid historical references and keys of analysis to understand midterms in general and those of 2010 in particular.

The most significant elements of the November 2010 election, Sabato tells us, are the damaging effect of Tea Party candidacies on the Republican victory in the Senate ; and the lasting consequences of Republican gains in state governorships and legislative chambers : in the wake of the 2010 census, they will be in charge of redistricting the states for national House and state legislative seats for the next decade.

The exit polls show how precise categories of the electorate have evolved since the presidential election of 2008. More than anything, they point to the major factor in the 2010 election –and most probably the 2012 presidential election–: the bad economy and its impact on voters’ attitudes.