It's more than just votes, you'd need to amend the Constitution itself to get rid of the Electoral College. Not only do you need two-thirds supermajority votes in both chambers of Congress to even propose an amendment (or get two-thirds of all states to propose a national convention, which has never been done), you'd then have to get three-fourths of all state legislatures to agree to ratify it (or have three-fourths of all state ratifying conventions ratify it, which has only been done once). And guess which party holds the majority of state chambers? I'll give you a hint: it's the party that knows it would stand to gain absolutely nothing if such an amendment were ratified.
Any calls to abolish the EC are grandstanding, plain and simple. Unless the Dems can win a massive amount of state and national elections to achieve a supermajority in both chambers of Congress and control of both chambers of 38 state legislatures, it's going nowhere. And if they actually managed to defraud that many elections, we have bigger concerns than just electing the President through popular vote.