National Popular Vote Interstate Compact

The National Popular Vote Interstate Compact (NPVIC) is an agreement among a group of U.S. states and the District of Columbia to award all their electoral votes to whichever presidential ticket wins the overall popular vote in the 50 states and the District of Columbia, regardless of which ticket won more votes in their individual state/district. The compact is designed to ensure that the candidate who receives the most votes nationwide is elected president, and it would come into effect only when it would guarantee that outcome.

Source: Wikipedia — National Popular Vote Interstate Compact (CC BY-SA 4.0)