This is an example of a perfectly formed malaphor. It is a congruent conflation (the best kind of malaphor, imho) of “smart as a whip” and “sharp as a tack”, both describing someone as highly intelligent. Smart and sharp are similar sounding words, and both idioms contain the “as a” words. Also, if you sit on a tack, it does smart, doesn’t it? The mashup is also heard in the Adam Sandler movie, “Big Daddy”. Here’s the clip:
A big thanks to Martin Pietrucha who heard this one and sent it in.
This malaphor was heard on “Hardball” with Chris Matthews. Political pundit Charles Cook was describing former Louisiana governor Edwin Edwards, now elderly, whom he saw recently. This is a congruent conflation of “smart as a whip” and “sharp as a tack”, both meaning to be very intelligent. Both idioms contain the same number of words, and “sharp” and “smart” have similar sounds. I can see where these metaphor can be easily mixed. A big shout out to “my ol’ pal” Beatrice Zablocki for hearing this one and passing it on!