I won't speak for Rush, but a lot of us have a big problem with Sean lately. My own area of disagreement is not ports or immigration per se, but the fact that he thinks any Conservative disagreement with him represents "kool-aide" thinking or some sort of "class" distinction. In some ways Sean does as much the populism thing--an example is HIS attacks on the oil companies--as the Conservative and he has spent some time bashing those of us who disagree. Still, I haven't totally given up on him because he, like us realize that a Republican victory is critical in November.
Sean is hurting the President with his neverending Bush bashing and acting like he's the one with the intellectual honesty.