When retard is used as a noun:

retard
n.
A slowing down or hindering of progress; a delay.

The anti-war protesters were desperately hoping to be retards, in that effort they may have indeed succeeded.

Protesters can act as retards in a figure of speech, much as I can act like an accelerant or a catalyst.

SDAI-Tech1 was desperately hoping to be a catalyst to the debate.

The other sentences I admit I didn't put a whole lot of work into and just threw them in off the top of my head:

The anti-war protesters were attempting to retard the war effort.

I think retard and impede are pretty much interchangeable right here both acting as verbs modifying the object the war effort.

The true bellyflop:

The anti-war protesters were retarding.

This was a totally incomplete sentence. You are correct it needed a object for the predicate. You got me. I bellyflopped like the fat girl in Shallow Hal. The kid is up in the tree crying for his daddy. The pool is empty.

I stand red-bellied and red-faced.

But now I'm going to try and go for Moebius digression award here by pointing out that despite my failures at proper grammatical structure, the intent was NOT to humiliate or insult you or anyone else - but rather to point out the dangers of putting labels on people.

Do you really believe the people here are warmongers in the word's true intended meaning? Don't you think we all would love to see Saddam and his family pack up and leave or be overthrown? Did you read the links on my "humanity" post? Do you think I read these and say, "Hey, what these tortured b--t--ds need are some MOABs falling near them?" Do you think I derive joy and pleasure that they need to be tearing up shirts to make readily available white flags and hiding them from Saddam's countless spies so they will not get killed before or after the war?

Do you think I, or anyone else here, wants to see some young Iraqi children put in front of a military target by Saddam's goonsquad so as to show their lifeless bodies to journalists feed the frenzy of the anti-war protesters worldwide?

Do you think I want anyone to come to their homes and find some of their loved ones slain by an errant bomb?

Is that really the sort of person you think I am? Tom? Frank? Larry? Matt? Ed? Scott? Gary? Does anyone else here really fit that definition?

By now, after hundreds perhaps thousands of posts, I would think we would have elevated ourselves above the classification of "warmongers" in your eyes.

SDAI-Tech1