Because they know Trump won't sign it, becuase he is actively working on behalf of Russian interests, against American interests. So is Moscow Mitch.
When that's pointed out, with facts to back it up, the trump lovers simply run away. They don't respond to your posts, or mine, or @FranchiseBlade's, or @NewRoxFan's or those of several others here that point it out because they can't defend it. They bury their heads in the sand, or start babbling bizarre conspiracy theories.