I think part of the problem is being "for" something. I think there are a lot of people who, for whatever reason, have a hard time committing to someone/something/a particular course of action. Easier to be against stuff.
Rush Limbaugh for instance. This is a crucial election and one in which you would think that fence-sitting would not be an acceptable position. But, Rush is taking great pains to not be for someone instead of using his influence for good. (Ha! I'm betting some of you here thought I meant you.)
Now's not the time for fence-sitting and attacking each other.
That's your opinion, and it's reasonable.
Just a couple of things to be aware of about Rush Limbaugh:
First, and most importantly, he is an entertainer. He's not a leader, he's not a politician, he is there to entertain so that he can make money. He must be doing something right, because he makes a boatload of money.
Second, it has been Limbaugh's history to not endorse anyone during the primary. Probably to avoid ticking anyone off, and keep contacts and listeners.
I don't give too much weight to what Limbaugh says for those reasons.