Let’s see . . . a toothless tiger has zero teeth.
To have less (or fewer) teeth than a toothless tiger, the proposal would have to have . . . Oh my God! The proposal has negative teeth!
Shaka. When the walls fell.
Tamak! The river Tamak, in winter!
It is my opinion that, in fact, the proposal has less teeth than almost any animal without teeth.
Obviously, Reid is as confused as a Mormon Democrat. Oh, wait. 
It could have been worse. The Senator could have done what lazy and sub-literate people do when they need to pump new life into an old metaphor: He could have added the word “literally”.
“This proposal is literally a toothless tiger!” That would make for an interesting bill signing ceremony.
I burning your toothless tiger!
When come back, bring tooth.
This is what we’re all taught in school (except when we’re incorrectly taught that a simile isn’t a metaphor at all), but the OP’s example is a simile, too. Similes are a specialized metaphor involving comparison. The most common comparison words are “like” and “as,” but “than” is one too. So, “Less teeth than a toothless tiger” is an ungrammatical, unmathematical (it has a negative number of teeth?), and unbelievably stupid simile.
You can’t handle the tooth.
And if Leaper were a public figure who would knock over his invalid mother to get in front of a microphone and a camera, I’d back you up on that.
People say dumb things. It’s just most of us aren’t being shown on CNN when we say it.
The tooth! Remember the tooth! The tooth…the tooth…the tooth…
This thread went well. I do see the point of the OP, but there is no way I am jumping into this one.
We used to have a poster named The Tooth. I wonder if this thread will smoke him out?
Aw, c’mon, Sapo. The water’s fine!
Fine for the piranhas with more teeth that a toothless piranha
Don’t we have a poster named gum?
But I agree, so few people can articulte ideas so… pizazzedly.
How about: “The proposal has less (fewer) teeth than my denture-wearing grandma.”
Denture wish there were more threads like this?
Tu quoque much?
Actually, Reid was wrong. The proposal did have one tooth in it. Since it destroyed his metaphor, this could be described as . . . all together now . . .
. . . An Inconvenient Tooth!