Illinois looks like they are about to pass one of those unconstitutional, unpopular, stepping-stone, marriage-in-all-but-name Civil Union laws. Though the language of their bill doesn't say that Civil Unions have all the "rights" of marriage, it does say that Civil Unions would offer the same "protections." One of the protections of marriage is of the right to procreate offspring together, marriage protects the couple's right to use their own genes to procreate offspring.
To make Civil Unions constitutional, they have to explicitly have different rights to justify having a different name. The right they should be missing is the right to conceive offspring together, which is also the essential, definitive right of marriage.
People should not have an equal right to procreate with someone of either sex, people should only be allowed to procreate with someone of the other sex. Attempting same-sex procreation requires genetic engineering to make artificial gametes from stem cells and would be unsafe, expensive, require big government regulation and research, and open the door to all forms of genetic engineering. It needs to be prohibited with a federal ban on making human beings by any method other than joining the sperm of a man and the egg of a woman.
At the same time, Congress should also federally recognize state Civil Unions that are defined as "marriage minus conception rights." Illinois should modify their proposed Civil Union bill in the Senate to add a clause explicitly stating that they do not protect the right to conceive offspring, so that they would be federally recognized immediately as soon as Congress enacts the Egg and Sperm Civil Union Compromise.