Professor Josh Douglas, an election law and voting rights expert and professor at the University of Kentucky, had this to say about the Electoral College: it creates a highly exploitable vulnerability in our presidential elections that could alter the results; under the U.S. Electoral College system and its current political demographics, "eight to 10 states will typically 'decide' a presidential election."
The reach of Russian interference, consisting of highly targeted social media disinformation campaigns in the United States, poses a national security threat and a threat to democracy in general. There is even strong evidence, uncovered by journalist Casey Michel that Russia has been backing the Texas secessionist movement for years through covert operations, including during the 2016 election.
The 2016 presidential election brought the issue of Russian meddling to the fore, as the Russians brazenly exploited social media in efforts designed to exacerbate partisan divisions and the political polarization in the American public.
The implications of our Electoral College system and of the winner-take-all method of apportioning states electors from each state, make the consequences of hacking elections, even on a small scale, potentially disastrous. They could in fact tip national presidential elections in whatever way the Russians decide. Senior Trump administration officials informed the public on August 2nd that Russia plans to interfere in this year’s midterm elections in November, as well as in the 2020 presidential election.
Senator Mark Warner (D-Va.), the Vice-Chairman of the Senate Intelligence Committee, has said, “a change in a national election doesn't require penetration into 50 states ... arguably, you could pick two or three states, and two or three jurisdictions, and alter an election."
Professor Douglas agreed, "the unique nature of the Electoral College, with the effect of making only a few states matter, means that it is presumably easier for a foreign actor to target just those states."
If we were to change the system to a National Popular Vote, the effects of hacking by foreign governments would likely have little effect. It would be very difficult for any actors, even with the backing of a nation state, to subvert an election in which every vote mattered.