Ben Nelson genuinely is a conservative Democrat. The Poole-Rosenthal rankings -- which most consider the leading measure of a congressman's relative ideology -- have, for years, ranked Nelson as the most conservative Democrats in the Senate. Call him Democrat #1. Evan Bayh, however, has not traditionally been number two. I went back in the rankings through the 107th Congress -- which began in 2001 -- to compare Bayh and Nelson's ideological consistency. The numbers on the Y axis represent how conservative of a Democrat each senator was. So #1 would be the most conservative Senate Democrat and #5 the fifth most conservative Senate Democrat and so on. The blue line is Bayh. The red line is Nelson.
To say Bayh lacks Nelson's steady hand on the wheel is a bit of an understatement. The two really interesting data points, however, are the 109th Congress, which stretched from 2005 to 2007, and the 110th Congress, which ended in January of this year. In the 109th Congress, Bayh's voting pattern suddenly develops an uncharacteristic liberalism. He becomes the 19th most conservative member, with a record more liberal than, among others, Joe Biden. As context, these were also the years when Bayh was preparing for the presidential run that he eventually aborted. In the 110th Congress, however, that flash of liberalism gives way to a career-high conservatism: He actually displaces Nelson as the Caucus's most conservative member. He's running for reelection in Indiana this year, but this is also the year that Indiana's tectonic plates shift and the state chooses that Obama guy. So I'm not going to pretend that I fully understand the motivations behind the sharp swings in Bayh's voting record.Bbut they're undeniably present, and seem to be keyed to political campaigns. Bayh is much steadier during the 107th and 108th Congresses, when no elections loom.
To say Bayh lacks Nelson's steady hand on the wheel is a bit of an understatement. The two really interesting data points, however, are the 109th Congress, which stretched from 2005 to 2007, and the 110th Congress, which ended in January of this year. In the 109th Congress, Bayh's voting pattern suddenly develops an uncharacteristic liberalism. He becomes the 19th most conservative member, with a record more liberal than, among others, Joe Biden. As context, these were also the years when Bayh was preparing for the presidential run that he eventually aborted. In the 110th Congress, however, that flash of liberalism gives way to a career-high conservatism: He actually displaces Nelson as the Caucus's most conservative member. He's running for reelection in Indiana this year, but this is also the year that Indiana's tectonic plates shift and the state chooses that Obama guy. So I'm not going to pretend that I fully understand the motivations behind the sharp swings in Bayh's voting record.Bbut they're undeniably present, and seem to be keyed to political campaigns. Bayh is much steadier during the 107th and 108th Congresses, when no elections loom. 
