I'm not a big comics guy, but I read the extended comic thingie on the link above. It seems the govt decrees that Mutants/Superheroes must be registered and controlled, or else. Not everyone agrees with a blatantly un-constitutional Registration Act for some odd reasons, including Capt America. Thus starts a nice lil war. Eventually Capt America decides that his views on the constitution and such are outdated, and that he should give up because wars are messy. Or something like that. In any event, the guy that decked Hitler, loses his spine and gives up to tyranny and oppression because some percentage of Americans think tyranny and oppression are more important than the Constitution.
Then gets clipped.
Sigh. Wolverine would never be a sellout.