Political Scientists Say Obama Might Be More Liberal Than Hillary
As James and Alex discuss below, the National Journal just released its 2007 rankings of Senators and found that Barack Obama had the most liberal voting record based on 107 “key votes” in the Senate in 2007. As legislative politics scholar Sarah Binder notes, this does not comport with Poole and Rosenthal’s NOMINATE scores, nor does it correspond with Lewis and Poole’s more recent Optimal Classification technique (via Kieran Healy), both of which show Obama to be much closer to the median Democrat.
Just to throw more fuel on the fire, I ran Clinton, Jackman, and Rivers’ item-response-theory-based ideal point estimator (sorry, it doesn’t have a fancier name–we in the biz just call it “CJR”) on all 433 non-unanimous rollcalls for the 110th Congress. The results suggest that Obama has the 9th most liberal voting record in the Senate, with rival Hillary Clinton in 11th place and very little daylight between them. Statistically, we can say that there is a (very slim) chance that either Obama or Clinton is the most liberal senator, as the 95% credible boundaries for both senators’ voting records overlap those of New Jersey’s Robert Menendez, who is nominally the “most liberal” according to the means. Both, incidentally, are slightly more liberal than John Kerry according to the procedure.
On the Republican side, John McCain appears in the middle of the GOP pack, as the 20th most-conservative senator, with no credible chance of being the “most conservative” (a rating that South Carolina’s Jim DeMint runs away with). McCain is, however, more conservative than GOP stalwarts like Orrin Hatch, Thad Cochran, Sam Brownback, and Lamar Alexander.