On the one side you had hundreds of people from immigrant's rights groups, on the other you had a dozen "Minutemen". You know about the "Minutemen", the idiots who have taken it upon themselves to "patrol" the border with Mexico.
The underlying cause for this appearance by the Asshats, sorry, the Minutemen, was a crime committed by an illegal immigrant. The immigrant in question is a minor who had already been arrested several times for violent crimes. The then committed a triple murder in a drive-by, using an AK-47. Horrible? Yes. Worthy of prison and/or deportation? Sure. However the underlying cause of this crime was not that he was an immigrant or an illegal immigrant.
It isn't as though no American citizen (of any race you care to choose) has ever committed murder. Surely no legal citizen has ever joined a gang or killed someone with a gun or performed a drive-by. I mean, if it weren't for the illegals, there'd be no gun violence or crime in the USA at all!
Using this crime as a prop for their xenophobic, racist crusade makes about as much sense as blaming the British for shipwrecks. It is a complete disconnect, but since so much of this country is completely irrational, they make the connection and get people to agree with them.