Notably, four representatives on the committee—Darrell Issa (R-CA), Zoe Lofgren (D-CA), Jason Chaffetz (R-UT) and Jared Polis (D-CO)—are fighting against SOPA all the way. Issa proposed an amendment yesterday that would have gutted the worst parts of SOPA out of the bill, though it unfortunately failed. Chaffetz's appeals to the potential compromise of DNSSEC finally got the thing shelved until real Internet experts can testify before the committee.
As the chief opponents of the bill are equally split, it shows this isn't a partisan issue (for once) but largely a who-is-bought-and-paid-for issue. I've watched a fair amount of the committee's meetings. The actions and attitudes of the bill's proponents has been shameful. Lamar Smith (R-TX), SOPA's sponsor, appeared determined to railroad the thing through the committee as-is no matter what. That he accepted a temporary end to discussion on the bill is a minor miracle. Smith basically lives in Hollywood's back pocket.
1 Sagan = Billions & Billions