The phrase "clueless idiot" means someone who is completely unaware or unknowledgeable about something and also acts foolishly or unintelligently. Full definition
He was scoffed at and accused of being a war monger by the «right - thinking» people of the day... the vast majority of clueless idiots who did not want to think of such nasty stuff. (remonline.com)
My wife and I just stared at her like a couple of clueless idiots. (romper.com)