The whole number proportional system sharply increases the odds of no candidate getting the majority of electoral votes needed, leading to the selection of the president by the U.S. House of Representatives, regardless of the popular vote anywhere.

It would not accurately reflect the nationwide popular vote; 

It would reduce the influence of any state, if not all states adopted. 

It would not improve upon the current situation in which four out of five states and four out of five voters in the United States are ignored by presidential campaigns, but instead, would create a very small set of states in which only one electoral vote is in play (while making most states politically irrelevant), 

It would not make every vote equal. 

It would not guarantee the Presidency to the candidate with the most popular votes in the country.