knock the props out (from under)

In The Times’ original review by Sheila Benson, she wrote, “Itami plays with the form of his film like noodle dough, stretching it, snapping it, hanging it out to dry. … What’s delightfully unsettling about ‘Tampopo’ is its lubricious mix of the sensual and the satiric; no sooner do we settle ourselves for one when the other comes along to knock the props out from under our expectations.”

“I thought I’d better come see for myself. You can’t depend on robots. Other people’s robots, especially. I also took the precaution of summoning the Dismantlers. They’H be here in one hour to knock the props out from under this horrible place.”

He threatened to lead a move to knock the props out from under the whole price control act when it comes up before Congress for renewal in June.

To repudiate this statement is to knock the props out from under the whole philosophy.