Donald Trump's " legendary" deal making is based on making a deal with someone and later reneging on the deal or screwing the other side, and then moving on to making a deal with someone else; not caring who he screws or hurts in the process.
Things are different with regards to government since the people who he may have to screw to get his deal made will be the same people that he'll have to be dealing with in the next deal that he tries to make.
The business community at-large has recognized Trump's deceitful techniques ; that's why no reputable banks will do business with him, few contractors and vendors will work with him, and fewer and fewer business people will make deals with him.
However, there is a veritable endless supply of people for Trump to make deals with worldwide. It will take a lot of time to run out of them completely.
On the other hand, the government and Congress has a limited number of people. When you start reneging on deals or screwing them, and then have to work with them again subsequently , they will not forget or forgive.
President Trump may "win" some in the beginning, but if he continues to "win" the way he's done it in the private sector, he'll quickly run out of suckers to screw.