I don’t know when Bachmann left Waterloo.
Bachmann could say “I always thought that John Wayne was from Waterloo. That’s what we used to think, in Waterloo, back in the day. Perhaps Waterloo “claimed” John Wayne as their own back in the day, when they shouldn’t have, when it was only his parents who lived there.” Perhaps Michelle could say she misunderstood the story when she first heard it, so many years ago, in good ol Waterloo, IA. Her case could be backed up by something like John Waynes name associated with Waterloo in the past. A John Wayne movie festival in Waterloo 30 years ago. Anything like that.
http://www.artknowledgenews.com/John_Wayne_Film_Series.html
Waterloo Center for the Arts to feature John Wayne Film Series
(2009)
“one of Iowa’s most beloved actors, John Wayne.”
So, a quick check shows that even today, in Waterloo, there’s “favorite son” attached to him. Not explicitly as a Waterloo resident, but as an Iowan.