Gay Marriage and Momentum

Most observers expect the same-sex marriage bill to pass the House, in the end. The state Senate, where the chamber's president M. Teresa Paiva Weed is opposed, remains the big question mark.

But observers say the fate of the bill in the Senate may depend, in part, on how it proceeds through the House. Of particular import: the size of the vote margin. Momentum matters in politics. And a thin margin could stall that momentum.