I’ll do my best.
I and many other people are opposed to this treaty because we don’t think that the United States government should pledge to do a whole lot of stuff that’s expensive and wasteful and serves little or no purpose and that violates the rights of individuals and private businesses. For example, from Article 8 of the Treaty:
States Parties undertake to adopt immediate, effective and appropriate measures:
To raise awareness throughout society, including at the family level, regarding persons with disabilities, and to foster respect for the rights and dignity of persons with disabilities;
To combat stereotypes, prejudices and harmful practices relating to persons with disabilities, including those based on sex and age, in all areas of life;
To promote awareness of the capabilities and contributions of persons with disabilities.
Measures to this end include:
Initiating and maintaining effective public awareness campaigns designed:
To nurture receptiveness to the rights of persons with disabilities;
To promote positive perceptions and greater social awareness towards persons with disabilities;
To promote recognition of the skills, merits and abilities of persons with disabilities, and of their contributions to the workplace and the labour market;
Fostering at all levels of the education system, including in all children from an early age, an attitude of respect for the rights of persons with disabilities;
Encouraging all organs of the media to portray persons with disabilities in a manner consistent with the purpose of the present Convention;
Promoting awareness-training programmes regarding persons with disabilities and the rights of persons with disabilities.
First of all, there’s no reason to believe that the United States has any need of more “awareness” about persons with disabilities. Pledging to spend money on publicity campaigns is therefore pledging to waste money. Why bother?
Likewise the idea that the government should address the portrayal of disabled people in the media is a waste of time as well as silly. The media are not the government’s business; it says so in the First Amendment. And with regards to education, don’t we already have enough goofy, politically requirements with which to meddle with school curricula? What’s the point of adding more?
And so forth. If you read the treaty itself, you’ll see that it’s a cavalcade of warm-and-fuzzy language, intended to be ambiguous in exactly what it’s calling for, but giving the government plenty of opportunity to meddle with the actions of businesses and local governments. Further, it does require the US government to establish a “focal point”, a “coordination mechanism”, and one or more “independent mechanisms” for overseeing all this blather, and while it’s obviously deliberately unclear what exactly this means, it certainly will involve spending taxpayer money.
Fundamentally, if advocates of the treaty think that ratifying the treaty is a good thing, why don’t they make a case for it, rather than just complaining about anyone who dares to act against it?