which president enjoy immense popularity by focusing on domestic issues and toning down the rhetoric in foreign affairs?

Ronald Reagan

Explanation:

By reducing influence in Foreign affairs, government will have more fund to be allocated for the use of its citizens. Meaning that the fund would be allocated for taking care infrastructures (roads, schools, etC), welfare, or for reducing unemployment in the country.

This type of policies tend to resulted in an increase in popularity among voters since they felt that they will be positively influenced by such action. Ronald Reagan managed to use this as a tactic to won his presidential election.