Can a town, through zoning, keep out those who can’t afford its existing housing? If not, can the state intervene? Those questions, touching on issues of jobs, race, class, sprawl, environmental preservation, and, of course, taxes, have wrought controversy and confusion. Gov. Christie’s aggressive approach to public education and unions may garner more attention, but his fight over affordable housing could become the true epic battle of the Republican’s first term. After losing skirmishes with the courts and Legislature on the issue, Christie now has targeted towns, demanding that most of them immediately turn over a total of $141.2 million left in their affordable-housing trust funds. As is his style, Christie wants to up-end the entire system of subsidized housing for the poor, and he is unsympathetic to complainers. “I’m not waiting anymore for these people to get their act together,” Christie said, referring to town officials who have yet to spend their money. He is just enforcing a law that set a deadline of four years to use the money, he argues.