Coming from the left, it seems odd that they are decrying a mechanism for electing the US President that is almost identical to the mechanism used to elect the European President (President of the European Union). I say odd, because the left constantly holds the EU and their democratic socialist governments up as the shining examples the US should strive for (as in "in civilized countries like...").
The United States is a collection of more-or-less sovereign states, joined in a common federal government. Somewhat like the EU. The member countries of the EU have distinct national interests but also share common interests with other EU members.
In the federalist government we have in the USA, each State in the Union gets a say in the election of the President. Each State has its own distinct interests but also share common interests with other States. The total number of members of Congress each state has is the basis for the total number of votes for President each state has in the Electoral College. Since each State has two Senators and at least one Representative, each state receives a minimum of three votes, with California--the most populous State receiving the maximum of 55 votes. The number of Representatives is currently capped at 435 (the apportionment of Representatives to States is adjusted every 10 years, based on the census), and the number of Senators is currently 100 (as we have 50 States), and the District of Columbia is also given 3 votes for a total 538 which implies that 270 votes are needed to win the EC.
Under the Constitution, each state is free to determine how they appoint their Electoral College voters and how they are supposed to vote. Currently, every State uses a popular election to select EC voters (and all but two use a winner-take-all method), but there's nothing preventing a State from passing a law allowing the Governor to simply appoint whomever he chooses (i.e., no popular election) or from using a proportional assignment based on election results.
The electors meet and cast their respective votes for President, and assuming there is a majority winner the process is just about complete. Let's ignore the fall-back rules if no majority is obtained as it is outside this discussion.
Virtually the same mechanism as the US Electoral College is used to elect the EU President, except it is the Parliament that elects the EU President and not a separate body specifically for the purpose. But the mechanism is very similar.
In the EU, each member nation in the Union gets a say in the election of the President. Each member nation has its own distinct interests but also share common interests with other member nations. The total number of members of the European Parliament each member nation has is the basis for the total number of votes for President each member nation has. Each of the 28 member nations has at least 6 MEPs, with Germany--the most populous member nation--receiving the maximum of 96 votes. The number of MEPs is currently capped at 750 by treaty. Occasionally, the binding treaties are modified to reapportion the MEPs, this requires unanimous consent and generally reflects changes in membership and population shifts. The EU President is elected by the European Parliament by a majority of its component members (which corresponds to at least 376 out of 750 votes).
MEPs are elected by popular elections in the respective member nations. At the appointed time, MEPs then vote for President, according to their respective party affiliation and national instructions.
How odd that the modern EU, most members of which are democratic socialist states, chose to use this 18th century structure that is so very similar to our own EC mechanisms.