JENA — A group of protesters stood outside the federal immigration center in this central Louisiana town a few weeks ago, calling for it to be emptied, when a truck rolled past and belched a plume of exhaust at them.
The driver circled around as the group faced a bank of TV news cameras set up in the brush across the road, then repeated the act — a greeting of sorts to a hamlet in the pines that once again has drawn a national media glare.
The protesters had trekked 230 miles that morning from New Orleans to support Columbia University activist Mahmoud Khalil, now in his second month at the detention center, where a judge that day had found him deportable…