To be clear, you don't need 51% of the vote or anything close to it with our current electoral college system. In fact, the system is so broken that you can win the presidency with as little as 21% of the popular vote:

https://maa.org/math-values/how-low-can-the-popular-vote-go/

This nonsense that "I won the election so I have a mandate from the majority of the American people to do as I please" is just not accurate.