Is Down syndrome the face of 47% or 10% club?

The Obama/Biden website features a letter of the week from Brittany.

Hello! My name is Brittany and I live in Mechanicsburg, Pennsylvania. I am 25 years old (but I will be 26 on October 3rd!). I am a registered Democrat and I have been voting since I was 18. I am one of the 47% of Americans who fall under Mitt Romney's definition of "entitled" and "unable to take responsibility for my life." I have Down syndrome.

The blog Speak with Authority noted that Brittany actually is not one of the 47% who doesn’t pay income taxes, because she did actually pay into the system.  They criticize the administration for exploiting Brittany:

 The Obama campaign has taken what could have been, with sensitive editing, a feel-good letter from someone who is doing her best under difficult circumstances and wishes to support Barack Obama into a dishonest, exploitive cheap shot at his opponent.  The president and his campaign should be ashamed.

It’s ironic that Brittany is a registered Democrat. This is the party that promotes abortion during any trimester, for any reason including sex-selected abortions.  Democrats are the ones who endorse abortion for the disabled.

Roughly 90% of babies diagnosed with Down syndrome are aborted.

Brittany is not the face of the 47%.  She is the face of the fortunate 10% whose parents chose life rather than abortion.