No Arnold is not popular. He just lucked out getting an opponent with the charisma of a flat tire.
That must also explain why Casey never got to the Senate.
Casey was only that bad of a candidate in the eyes of die-hard extreme Casey haters like yourself and Walter. I remember you guys insisting that during the MTP debate Casey would do so horribly he would make Bush at the first debate look like a master debator and Santorum would inevitably gain a few points. Casey also didn't have a primary opponent that ripped the hell of him.
Arnold is certainly not more popular than Bill Weld or Tony Knowles, that's for sure.