I don't think a Court could abolish the Electoral College, but the Federal Courts could do a lot of damage to it, following their "one-man, one vote" precedents. Baker v. Carr did not exactly ABOLISH State Senates, but it did change their design and their character by voiding 50 State Constitutions which allocated State Senate seats according to non-population based schemes.
Of course, States appoint their electors, and they are not required to do so by people voting. It would be perfectly constitutional for no persons (except State legislators) to be allowed to vote for Presidential electors.
A court could decide, however, that for states which choose to allow popular voting as the mechanism to appoint electors (as all 50 do at the moment, plus the three electors Congress awarded itself in 1960), that the distribution of electors would have to follow the popular vote in that state.
I mapped the result of such a system on the 2016 election, and I came up with the following:
Clinton 256.13 EV, Trump 249.74 EV, Third party 32.13 EV.
This distribution is not based on national popular vote, but on popular vote percentages in each state - for example, in California under a "one-man, one vote" modified Electoral College, Trump would have gotten 17.39 EV instead of zero, but in Texas Clinton would have gotten 16.43 EV instead of zero.
Any state can pass a law now to award their Electoral College vote to the winner of the national popular vote on its own. Why will no state step up and unilaterally do this to be a leader for the cause?
Why are they hiding behind this need to have a compact of 270 votes lined up before making the change? Why won't some liberal state lead by example, take that first step, and just do it now?
-PJ
After Trump is done packing the courts, you won’t have to worry about them for 50 years.