The Constitution is no fount of wisdom in all things. In addition to providing for Electoral College, it provided support to slave owners (the actual reason there is an electoral college), assignment - not election - of Senators and enough internal inconsistencies to keep the Supreme Court in lawsuits ever since. So, simply pointing to the Constitution and saying "See!!" is not adequate.
The Constitution is a fine governing document - but the people of America must support the democratic process as implemented. And, as implemented, Donald Trump won. This might lead to the end of humanity or the end of democracy or maybe just an odd four years.
But invalidating the election, after the fact, WILL mean the end of American Democracy. And, love of hate Trump, it isn't worth loosing that.