Seventeen Senate Democrats joined with every Republican in voting to roll back some bank rules. Many of those Democrats did so as they push for political survival. The Senate voted 67 to 31 on Wednesday to ease regulations on all but the largest banks, in what would become the biggest rewrite of financial laws since the Dodd-Frank reform act passed after the global financial crisis. The legislation would raise the level at which banks are considered "systemically important" and exempts...