Electors in the electoral college are given according to the number of representatives in Congress; this is the sum of the House delegation, which is proportional to the population, and the Senate delegation, which is two senators for every state. This means that the number of people per electoral vote ranges from 500,000 people per electoral vote for California to 140,000 people per electoral vote for Wyoming. It is thus possible for a candidate to lose the popular vote but still win the electoral college and become president.
In recent years, the electoral college has benefited the Republican party, because it gives more electors proportionally to smaller states, which skew Republican. A president losing the popular vote and winning the election has happened four times since all electors were popularly elected: Hayes in 1876, Harrison in 1888, Bush in 2000, and Trump in 2016.
If the Republican candidate wins the electoral college in 2020, will they lose the popular vote?
This resolves according to the figures listed on Dave Leip's US Election Atlas after the electoral college votes have been certified by Congress. The electoral college winner and popular vote winner are considered to be those with the plurality of electoral votes and popular votes, respectively.