Placing it there was the idea of Richard Wukich, an art professor at Slippery Rock University in Pennsylvania.

VOA: special.2009.06.22

We don't want to get the Supreme Court into making fine distinctions about what is better than others, because that will lead us down a slippery slope.

VOA: special.2011.07.04

It is a slippery slope. And, we're not careful, before we know it all of us will be in a much more dire situation."

VOA: standard.2009.11.11