Apparently you do not understand how the congress works.
If you have a majority, you have the speaker of the house and the majprioty leader in the senate.
Each of whom have almost total power of what legislation is brought to the floor.
Lose the majority and the dims decide on the music.
The set the rules and they determine what legislation will come up for votes.
Right now I am sure you would agree that the Republicans have a majority in both the House and the Senate. But their actions in many cases are far from what the people that voted for them would like. Just a couple of examples - what have our Republican majorities done to restrain government spending? Have they even brought a budget to the floor to be voted on? How about real reform and a replacement for Obamacare? How about serious hearings into what is going on at the IRS, or the DOJ, or the State Department.
So having a majority doesn't do much good when that majority is made up of politicians who are really more intent on preserving their positions of power and personal interests than advancing the agenda of the voters that elected them.