Umm. This is fake news.
Nevada is already a winner take all state, as are all of the states except Maine and Nebraska. Whoever won the popular vote in Nevada already got the states 6 electoral college votes, as Clinton did in 2016.
So this law changes nothing.
Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed. But when the right to vote at any election for the choice of electors for President and Vice President of the United States, Representatives in Congress, the Executive and Judicial officers of a State, or the members of the Legislature thereof, is denied to any of the male inhabitants of such State, being twenty-one years of age, and citizens of the United States, or in any way abridged, except for participation in rebellion, or other crime, the basis of representation therein shall be reduced in the proportion which the number of such male citizens shall bear to the whole number of male citizens twenty-one years of age in such State.
Deciding elections by popular vote would be even worse than your map would suggest. It would mean a system where elections mostly driven by votes in New York City, Washington DC, Chicago, Houston, Los Angeles, San Francisco, and Miami metro areas. With a nation-wide popular vote, mostly Republican rural votes even in states like Texas get washed out by the mostly Democrat metro urban-suburban vote.
This will be great. Trump is GOING to win the popular vote by a landslide. This will get repealed on day 1 of the 2nd trump term.