Planned Parenthood, a company that performs mass abortions, are selling the body parts of their victims.
"Are" should be "is," and "their" should be "its." You noticed it was a singular subject when you correctly used the singular "a company that performs" in the adjectival dependent clause.
You're also overgenerous in your use of commas. For example:
Companies, and now the Obama administration, are now punishing states ...
The commas shouldn't be there. If you'd left out the commas, you might have noticed the redundant "now."
These little details distinguish elegant writing from effective speech. If you were presenting this material verbally at a town meeting, it would be great as it is. You've got organization, supporting detail, and a dramatic conclusion. In writing, following the conventions of grammar is a strength. Even if the conventions seem irrelevant or unnecessarily constricting, they force you to build your argument on powerful words and solidly logical construction.