Not sure about that. Lots of voting systems don't vote for parties directly either. And I would say the two parties in the US are extremely strong, FPTP seems t

Not sure about that. Lots of voting systems don't vote for parties directly either. And I would say the two parties in the US are extremely strong, FPTP seems to reenforce that. It might also lead to the parties accepting some level of dissidence from some members -- better for a blue party to have a slightly red-ish congressman in a red state than to cede it to the other party. But I don't think that really weakens the parties because it goes both ways. Minor parties and coalition governments in other countries function in somewhat the same way. It's not uncommon for a party to win but not gain absolute power in the legislative branch of government, and have to compromise with others to pass laws and spending bills.