Senator Olympia Snowe’s (R-Maine) announcement today that she will not seek re-election this year means that the next (113th) Senate will be absent the two most centrist members of the current Senate (Sen. Olympia Snowe is the most liberal Republican, Sen. Ben Nelson (D-Nebraska) is the most conservative Democrat and is also retiring– see the rank ordering here).
Snowe’s retirement means that the Maine Senate seat is now a likely Democrat pickup in the 2012 elections. Indeed, Snowe’s replacement in the Senate is likely to be a liberal Democrat. Below, we use first dimension (liberal-conservative) DW-NOMINATE Common Space scores, which allow for the comparability of ideological positions between chambers and across time, to plot the locations of the Maine congressional delegation and the distributions of the parties in the current House and Senate. Both Maine Senators — Sens. Susan Collins (R-ME) and Olympia Snowe (R-ME) — are clearly among the most centrist congressional Republicans. The two current Maine Representatives — Reps. Michael Michaud (D-ME) and Chellie Pingree (D-ME) — both have good favorability ratings in the state and would make strong candidates for the now-open Senate seats. We also include former Rep. Tom Allen (D-ME), who gave up his House seat to run against Collins in 2008, who is a potential candidate. Rep. Michaud is the most moderate of the three, though were he to enter the Senate he would be near the mean of Senate Democrats. Alternatively, Rep. Pingree would be among the most liberal Senate Democrats.