I bid 2♠ michaels here on the theory that it tells my partner the most information, that I have two 5+ card suits, hearts and a minor, and since they have spades, I don't have a strong preference for hearts or clubs -- we'd probably have to go to 5 anyway. And without the middle honors in hearts and strong club honors, I figured a club fit would be just as good. Partner says I should have just bid hearts here which makes sense too, given the 7 card suit. Given that I was the only person to use michaels there, I guess I was probably wrong, but could anybody perhaps explain why?
Incidentally, partner compounded my error by bidding 3♦ when he had 4 card heart support. I passed out 3♠, perhaps another error, because I figured they could make 4 and I assumed they must have KQJ♥. They made 3♠+1, but we could have made 5♥, or even 6 with an exceptionally unlikely diamond or heart lead.
Anyway, any thoughts would be appreciated. :-)

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1♠ ?