Protecting gays is only one element, though the most publicized. The bill considerably expands federal jurisdiction over hate crimes in general, for all categories, by eliminating the current requirement that the crime occur while the victim is engaged in a federally protected activity. That jurisdictional limitation has kept federal involvement very limited in an area where state authority has traditionally reigned. The new law also calls for more federal resources to be expended on all classes of hate crimes. The veto of an amendment merely adding sexual orientation to existing federal law would pretty clearly reflect an anti-gay double-standard. A veto of this much more comprehensive bill does not.
To test this proposition, and to put gays on a par with other groups often targeted for hate crimes, Congress could simply amend the 1968 federal hate-crimes law to add protection for sexual orientation. Then we'll see what the President does.
I take the point. The situation is more complex than my first post argued, although I suspect the president would veto such an addition to the federal hate crimes law as well. But we don't know that for sure from the bill proposed and the veto threatened. That's a missed opportunity. Maybe if the bill is vetoed, a cleaner, simpler one can be brought forward.