This e-mailer’s guess makes some sense:
Beyond the immensely important cloture vote planned for tomorrow evening is the intriguing possibility that Presidential contender Sam Brownback might commit political suicide right there on C-Span for all the nation to see. At least Senator McCain can make the political rationalization that a number of centrist Republicans and Independents might continue to support him and keep his campaign afloat, but what becomes of Senator Brownback should he pull the trigger and alienate the grassroots (which is all he’s got). It would be one thing for him to sacrifice himself for a bill that he strongly endorses, but why destroy his presidential bid for a bill he himself says is deeply flawed?
I say Brownback votes “no” on cloture…..