Why do some liberals consider anyone that disagrees with them a neo-con?

I disagree with that statement NEO-CON!:)
Truthfully to me, the whole Conservative/Liberal thing is pretty sad. We're all in the same boat.
I think if most of the people we're asked the same series of questions to find out where they stand on certain issues, that some of their answers will be from a conservative point of view and some from a liberal point of view. Unless there hardcore either way.
I believe our immigration laws must be respected, our government should be much smaller, and that all law abiding citizens have a right to own a gun. But I also believe that woman should have reproductive freedom.

If they do, they are ill informed or are just grabbing the insult du jour. There were actually just a small cadre of Neo-Cons in the Bush administration. They are far from being the core of the conservative movement.

Good question. I think it's because they are simply name calling. I often get called a "right wing fundamentalist creationist" because I say that I don't think evolution and intelligent design are mutually exclusive. Another one that gets bandied about is "racist". I've been called a racist because I think our immigration laws should be respected. It's just their attempt to gain support by using "buzzword" insults. All these insults are designed to elicit an emotional, rather than intellectual, response.

Why do Neo-cons consider anyone who disagrees with them a Liberal?

Because politics isn't about truth; it's about power.

the same reason they walk around with a broom up their butts. It makes no sense but they do have clean floors.

It goes both ways. It's easier than thinking, and neither side likes to do that very much.

that is why because you do not agree with them, just like others.

It beats thinking.