It's not a slippery slope argument if....

[jackfaire]

It is the ultimate goal.

For example if your ultimate goal is to legalize gay marriage and so you are trying to pass laws to legalize gay marriage and then people argue,


"Next they will want to legalize marriage to cats, dogs etc."

This is a slippery slope argument.

However if your stated goal is to abolish slavery and you free all of your slaves it is not a slippery slope argument when your opponents say,

"Next he is going to help pass laws forcing us all to give up our slaves"

Because the argument does in fact coincide with your stated goal to do just that.

[bara]

A slippery slope argument is also valid when dealing with institutions that often take the simplest matters to extreme. Many zero tolerance policies are good examples of this.

For instance:
No paper at all at a call center for security- cant even have tissues to blow your nose but you cant take a break every time you need to blow your nose.
No weapons at school- kid gets in trouble for drawing a picture of a gun