See post 47 of this thread; there is NOTHING the Republicans can do to stop it. They cannot filibuster, and it only takes 34 Democrats to ratify the treaty. There are more than 34 guaranteed-safe Democrat Senate seats, so even raising the hue and cry won't help; you cannot vote out those who would ratify the treaty.
Key word “silent”. Yes they do not have a majority, but they sure can raise hell about it. The tea party is a lot louder than the Republican party.