Pickle barrel e waterfall - Tradução em português

[N001]

"But this week when Romney said that he wasn't concerned about the very poor in this country, he jumped in the pickle barrel and went over the waterfall"

I know that pickle barrel is "barril de peclis" and waterfall can mean "cachoeira" but I couldn't understand the real meaning of this phrase.

Would be the translation like this: "Mas está semana quando Romney disse que ele não se preocupava sobre os mais pobres nesse país, ele pulou no barril the picles e foi em cima da cachoeira" ?

This translation doens't make any sense to me. Did I translated these words wrongly? Or this can be an idiom? Or I simply translated to portuguese wrongly?

[Thomas]

I would suggest translating as "he committed political suicide". He said something dumb, something that was going to cost him votes.

Think about it. If you get into a pickle barrel and go over a waterfall, it's almost an act of suicide. You have little chance of survival. If you are a politician and say you are not interested in the very poor, it's an act of political suicide. You have little chance of political survival.

[N001]

Thanks, Thomas, now I see more clearly what this phrase means.