Yeah, both my dad and I are on the TSA terrorist watchlist, not because of anything we've ever actually done, but because our last name, Johnson, happens to be shared by a known terrorist. That means that every time I try to fly anywhere, the airport runs extra checks on me because of my name. Some would take offense to this name based profiling. Not me though, I think it's fucking hilarious.
So, if I may offer some advice, just laugh about how stupid and racist the people who continue to suspect your father are, because the unfortunate truth is that there's not too much else you can do. Not until we as a people learn to look past race and fear at least, and one might be forgiven for thinking that time could be a little ways off.