I think Trump is playing the Democrats again. I am waiting to see how this plays out. The last time Trump did this was with the DREAMers. He offered the Democrats everything they wanted and more, and they walked away. He offered again with gun control, and the Democrats are now going whole hog on this. Here are the current House Bill (hr5087) and Senate Bill (s2095) about the Assault Weapons Ban of 2018.
I hate to quote Nancy Pelosi and admit she's right, but "they have to pass the bill to see what's in it." If you know anything about Parliamentary procedure (I keep a copy of Robert's Rules of Order, Newly Revised, 11th Edition on my desk). A Congressman can stand up and say, "Mr. Speaker, I move that concerning hr5087, the lines starting at page 18, line 7 and proceeding to page 19, line 4, inclusive, be stricken from the bill." If that motion is seconded and voted on in the majority, then the exemption for federal, state and local government entities to purchase any of the weapons in the ban is removed. That might change things a bit. It would be simple, would it be easy? Of course not. However this is the method one party puts "poison pill" riders in a major bill from the other side of the aisle to make the bill fail.
Like the Affordable Care Act, I cannot see a single Republican changing the bill or voting for it. They want the Democrats to vote for this, in unanimity because that will show the American People how the Democrats regard the citizens of this country. These bills have less than a 5% chance of reaching Trump and I am sure he would never sign the bill, because he knows his approval rating and his base would dwindle to almost zero within minutes of the ink being dry. What it has done is clearly shown that every sponsor and co-sponsor of these bills and everyone who votes for them, unless they are in the super-blue districts or states, are going to have a very tough time retaining their seat in the midterm elections in November, regardless of party.
If this issue is properly played by Trump and the Republicans, the midterms should be beyond devastating to the Democrat party.