Where the rubber meets the road
Democrats will excuse their vote for this by saying it’s just a “process” vote to allow the Senate a say in such an important vote. But they know they are actually interfering in delicate negotiations by doing this and they know that if they get involved to the extent the Corker bill anticipates, the deal will likely fall apart because the Senate will vote it down. They know that by voting with the Republicans they will be helping them get what they want which is more war.
They all have their local issues to deal with. We get that. But this is war and peace. It’s about nuclear proliferation. It’s arguably worse than voting for the Iraq war since the consequences are so grave.