Showing Independence?

Interesting:

Republican leaders are struggling to maintain a unified opposition to the White House's financial-regulation revamp, which is emerging as the next big test of the GOP's ability to counter the administration's agenda.

Democrats, assuming they can maintain discipline among the 59 Senate votes they control, need only one Republican to surmount any filibuster. At least one, Maine Sen. Susan Collins, is resisting pressure to sign a letter committing all 41 GOP senators to back such a delaying move, according to a person familiar with the deliberations. Such a strategy would effectively block action on the legislation and push the White House to bend to GOP demands.