Of course it is possible, unless you mean politically. Then I would have to grant you that politically Sanders would run into the special interests represented by our congressmen and senators. Nevertheless, go to his website, if you would, and look at the section entitled "How Sanders would Pay for His Plan ". It's Very doable from a budget standpoint.
Let me, for example, just mention a single component of the Medical Cartel that is crucial to their maintaining control: The Food and Drug Administration. A President Sanders could completely break the strangle hold the pharmaceutical industry has on prescription drug pricing and dispensing with a single stroke of the pen in combination with his choice as FDA commissioner. Similarly, a President Sanders as Commander and Chief of the Armed Forces would have veto power over military operations and procurement. So although Congress controls the purse strings, the President controls to a large extent how money in the purse gets spent. The President, through his Executive Department Heads can effect regulatory decisions. So do not think for a moment that a strong, cantankerous President Sanders wouldn't be every bit Congress's match. His Twenty five years of working with Republicans and Democrats in Congress would be a tremendous asset.