clutching at straws
Out of desparation, the act of reaching or stretching for a solution, no matter how irrational or inconsequential. Literally - a drowning person who, unable to find any substantial floatation immediately at had, attempts to save himself from certain death by grabbing hold of a few stray pieces of straw floating on the water within arm's length.
The Senator from Florida, caught red-handed sending lewd and lascivious text messages to underage male pages, was clutching at straws for an alibi and escape. Alcoholism? Resignation?