double modals (was: fronted /oU/)

[P2052 at AOL.COM]

I've never perceived a "politeness" function of these "serial modals."  In
fact, I have sensed more of a "doubt" or "hesitancy" motive on the part of
the speakers--a phenomenon quite similar to the ever-increasing pairing of
"kinda" and "sorta," as in "I kinda (=kind of) sort a (=sort of) think I'll
be able to do it."  These serial modals occur in the same context (Cf. I
think I might could/can/would do it.)
                                     PAT