In the 70's Gerald Ford was my congressman (Grand Rapids, MI), before his VP and Prez jobs. If he had a Bob Jackson, he never used it in his District, or if he did, did so on low key personal excursions. This seems to be the case with Celebs. In my experience he never hooked up with the local bike club to promote good will, to represent cycling interests or to further his political goals. He did have homes in D.C., Vail and Palm Springs, CA (or at least those are the places that stories about him originated) so maybe he rode his bike over there.
The current prez seems to be a pretty avid biker (since his running injuries) but you rarely see press coverage. Ditto with other current celebs (e.g. - Robin Williams, Sheryl Crow and rumor has it Madonna) but further discussion of this matter is off topic.
One of the founders of the local bike club, the Rapid Wheelmen, was a fan of Bob Jackson and had a very nice canary yellow and ruby accented Bob Jackson bike in the 70's. It doesn't seem like the bike club founder would be asked for advice on bike brands by his congressional rep but you never know.
Todd Teachout
Hercules, CA