cut the ground out from under
cut the ground out from under (one)
To suddenly cause problems for one. I plan to cut the ground out from under the prosecutor with this line of questioning.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
cut the ground out from under someone
Fig. to destroy the foundation of someone's plans or someone's argument. The politician cut the ground out from under his opponent. Congress cut out the ground from under the president.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.