Rick Santorum is a much better fit with Trump’s message especially on immigration and trade. He helps with Christian voters and social conservatives, Trump’s weak spot. He helps in Pennsylvania and probably Ohio, since he’s from Pittsburgh, close to Ohio. Santorum came close to beating Romney in the Ohio primary.
Santorum would be my favorite pick too, but I assume he is not under consideration.
Trump doesn’t need a mini-me that lost a Senate election. Rubio would be a smarter puck for Trump. A wink and a nod to LaRaza and poke in the eye to his birther constituency. Lol.