Corker would bolster what many of Trump’s critics are claiming is a lack of foreign policy expertise. While that may be true to some extent, picking Corker for VP, Secretary of State or any other senior position in the administration, would alienate a LOT of voters who actually pay attention, i.e., conservatives.
All the people claiming Trump has a lack of ‘foreign policy experience’ are the people who have gotten us into war after pointless war, made us untrusted by our allies and unfeared by our enemies.
Trump is happy to gladhand those guys and say “that guy is great” about any one of them, but he isn’t looking to appease them or to include them in anything important. His desire to keep them out of the loop isn’t about ideology; it is about competence. He doesn’t trust their judgement and doesn’t want them anywhere near the levers of power. Therefore, the idea that Trump would pick this guy (at least for that reason anyway) is completely asinine.