You have to keep in mind too that the way the electoral college works today is the democrats start with 86 electoral votes for NY and CA. These are awarded the minute the polls close; no count necessary. They don't need to campaign in these states, nor is it meaningful for republicans or anyone else to do so. The actual election is for the remaining 452 electoral votes, of which the democrats need 184 and anyone else would need 270. This is a tremendous advantage - why would they want to give this up despite a chance of losing the popular vote? In CA conservatives tend to live in the central valley and the northern parts of the state where voting means getting in your car and driving to the poll booth. Why would they, other than to vote for state initiatives? Their reps usually win with a wide majority anyway. As a result, conservative voter participation in CA and NY is relatively low. The democratic presidential candidate usually walks away with a 65-35% popular vote.
One doesn't have to be a genius to understand why the democrats haven't been in a hurry to abolish this system - it's massively rigged in their favor. No red state, such as GA or TX, comes close - republicans actually have to campaign there. As a result, the largest state collects a huge number of democratic popular votes, perhaps out of proportion to the electoral college votes, and hence tends to skew the national popular vote. Democrats, because of the CA-NY hegemony risk losing the popular vote exactly because of the electoral college advantage. In their mind, this is obviously an acceptable risk, because the elections are about electoral votes, not the popular vote, and why would they give up their advantage?!
Switch to a popular vote and you'd see campaigning in CA and 65-35 would quickly turn into 55-45 or even 53-47. A 30% margin would drop to a 10% or 6% margin. A 6% margin is still very dominant, but it's not comparable to the electoral college advantage they sit on today. I'm all for doing this, because a voting system where millions of votes, be they conservative rural californians or urban east coast minorities, are discouraged from voting is a structural wrong that should be fixed. However, I think it would make it significantly harder for democrats to win the presidential election, not easier. To bill it as making it easier would just be dishonest. Crassly speaking it's not in their interest to abolish the electoral college in favor of a simple popular vote count.