As the Senate headed for a showdown this week over a Democratic threat to erode the filibuster rule, a senior Republican was musing about the party leaders he'd known over his long career.It should never have come to this, he said sadly. Previous leaders -- like Republican Howard Baker and Democrat Robert Byrd -- would have found a compromise long before the entire Senate came within hours of blowing itself up. Their counterparts today -- Democrat Harry Reid and Republican Mitch McConnell -- barely speak to each other, except to hurl insults.