In the following context:
I'm clutching at straws here. I'm trying to imagine how a woman could fail to be offended by being called a "hole".
What's meant by "clutching at straws"?
Imagine that you are about to fall. Imagine that you grab / grasp / clutch at a bunch of straws to avoid falling. It is a desperate move, because the straws will never be able to hold your weight and you know it, but you do it regardless (because it is your last hope).
The expression above could be translated as:
"It is almost impossible for me to imagine a situation in which a woman will not be offended by being called a..."
It means “looking for a way to do something which is actually hopeless and unattainable”. Like trying to stop yourself from falling by grabbing onto something that’s not going to hold your weight.
Often, it’s used to describe taking an untenable position in a discussion – trying to justify something by coming up with propositions that just don’t make sense.
to depend on something that is useless
to make a futile attempt at something
trying to find some way to succeed when nothing you choose is likely to work
trying to find reasons to feel hopeful about a bad situation
The idiom originated with Thomas More’s Dialogue of Comfort Against Tribulation (1534).