Lucifer, I think most of congress' problems are related to weak president along with very weak congressional leaders. I think a strong president will shake things up enough that some coordination will start to happen.
The Democratic side of Congress is indeed strong, they show that by leading Ryan/McConnell around by the nose and forcing them to give them EVERYTHING they want. In reality Harry Reid is still in charge of the Senate and the dems still control the House.
A President Cruz will have a difficult if not impossible task of getting anything through as the democrats hate him and half of the Republicans (including the majority of Senate Republicans) despise him.
Now all of this is based upon the current make up of Congress. Come November that could change dramatically.
Bottom line is this: Unless the President can form a coalition in Congress and the Senate, any and all proposals by a candidate is nothing more than vote pandering.