You can fire “at will” employees for any, or no, reason at any time.
“You can fire “at will” employees for any, or no, reason at any time.” For the most part, yes, but there exceptions, such as “implied contract.” And of course some people are in “protected” categories - ie, disabled, minority, old - and should be handled with kid gloves.
If you fire someone because they have an Obama bumper sticker on their car, their lawyer will give your Employee Handbook and Personnel Department’s Policies and Procedures the once over, to make sure you didn’t violate them. So plan ahead. (grin)