The CBO does a good bi-partisan job of predicting the outcome of a bill but as with any prediction that is all it is.  Depending on where you are on the political side, if it favors you than it's great.  In 2010, the CBO predicted that Obamacare would have 21 million individuals buying healthcare by 2016 but as of 2016 only 11 million did so.  All CBO is a political gauge so I wouldn't put heavy stock in the CBO getting it right.  The Democrats are like little kids pouting and whining with their sitdown resistance.  I have to say the Republicans are no different.  I say this that Trump is working his butt off to make good on his promises unlike many politicians.