shoot someone's fox
shoot (one's) fox
To undermine or thwart someone's plans, efforts, or ambitions by taking action that pre-empts them or makes them redundant. Primarily heard in UK. Congress may have shot the president's fox, though, with a bill that he cannot politically afford to veto, but which leaves him with no opportunity to pass his signature healthcare plan.
shoot someone's foxthwart someone's plans or ambitions by pre-empting them.
The expression comes from the world of fox-hunting, where shooting a fox, which robs the hunters of their sport, is viewed with great displeasure.
2004 Scotland on Sunday The Democrats had planned to make unemployment a key issue in their campaign: Dubya, with his tax cuts, has shot their fox.