There's a longstanding debate over the reasons for the Republican victory in last year's midterm elections. On one side are those who say the great shellacking was inevitable because of America's high unemployment rate. On the other are those who say that the Democratic policy agenda shouldn't be dismissed as an important factor.
Well, Stanford political scientists David Brady, Morris Fiorina, and Douglas Rivers have a great piece in the new Policy Review that lends support to those who say that health care and cap and trade worsened the Democrats' losses:
The president’s party typically loses seats in midterm elections; the average loss for first term Democratic presidents in the postwar era is 30 seats. A very poor economy and a president below 50 percent in approval by themselves would generate significant losses for the incumbent party. But political science forecasting models based on the 'fundamentals' badly under-predicted the Democratic seat loss — several even forecast that the Democrats would easily retain their House majority.
Our hypothesis is that by pursuing a policy agenda to the left of the electorate’s comfort zone the president and the House leadership exacerbated the problems for Democrats from moderate to conservative districts — especially the districts captured in the 2006 and 2008 elections. Three-quarters of the Democratic candidates running in the 48 districts carried by McCain in 2008 lost. Tellingly, eight of fifteen who voted no on both health care and cap and trade survived, while only three of sixteen who voted yes on one or the other survived, and all seven of those who voted yes on both bills lost. By pushing highly controversial legislation, the Democratic leadership in the House of Representatives caused the party to lose significantly more seats than they would have from the poor economy alone.
Read the whole thing here. It's essential if you want to understand contemporary American politics.