In the current two party system, voters often feel compelled to vote for a candidate of a major party not because they prefer that candidate, but because that is the best way to prevent the other major party candidate from being elected. This works to prevent third party candidates from being seriously considered.
There are voting systems that allow voters to indicate which candidate they prefer while also indicating which other candidates are acceptable. The Condorcet methods, for example, work this way.
Please support changing the method of electing the President of the United States to such a system.