Ryan is getting the next highest Twitter buzz, according to the firm. He and Rubio show consistently strong results, although Twitter buzz may also accompany their work in Congress. The firm tracks "buzz" by counting the number of mentions each candidate's Twitter handle receives.
Pawlenty saw a spike early last week, likely due to a New York Times story claiming Romney's choice had been narrowed down to Pawlenty or Portman.
This week, former Florida Gov. Jeb Bush -- another name often thrown around as a good choice for VP -- personally urged Romney to choose Rubio as his running mate, according to the Associated Press.
Image courtesy Digital Accumen.