Ken,
Concern for a politician's re-election is always paramount. In this case it means they didn't have the popular support or political capital to oppose in any coherent fashion. But when a politician has relevant personal experience, that brings with it a wealth of political capital. By that, I mean it's much easier--with voters back home--for a senator who's a doctor to feasibly oppose a popular health care proposal. Or for a Congressman who served as a maneuver commander to oppose a widely accepted defense policy.
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