JOEL K. GOLDSTEIN, a law professor at St. Louis University, is a leading authority on the United States vice presidency. People seem to respect him anyway.

“My wife says that I am an exotic plant that blooms every four years,” Professor Goldstein said.

Indeed, this is the height of the quadrennial running-mate season, a period of amplified interest in an otherwise afterthought of a job. If Tom Brady has Super Bowl Week and Gisele Bündchen has Fashion Week, this is Mr. Goldstein’s Go Time. Reporters keep calling him, seeking a hint of authority in what is essentially an exercise in guesswork about whom Mitt Romney will choose: Pawlenty or Portman? Rubio or Rice?

Professor Goldstein, who owns no inside knowledge of the plans of the presumptive Republican presidential candidate, is happy to speculate, just like the really smart experts do on cable television every day.

Except that Mr. Goldstein, 59, can do it with a gravitas conferred by advanced degrees, expertise on the 25th Amendment and authorship of an acclaimed book on the vice presidency.