Patricia Arquette -- Cheney's Daughter

8/5/2009 2:00 AM PDT BY TMZ STAFF
Here's "Medium" star Patricia Arquette at an event in L.A. on Tuesday (left) -- and Dick Cheney's daughter Mary Cheney as she appears on the cover of her memoir (right).

patricia arquette and mary cheney

One of them has been in a committed long-term relationship with the same person since 1992.

We're just sayin'.