Every week the campaign dollars pile up, by the tens of millions, by the hundreds of millions, to a level never before seen in American political life. Outside groups now say they plan to spend $1 billion on behalf of Republicans in the November election, which will probably be twice the level raised by groups supporting Democrats. Even the slush-funders of the Watergate era would have been slack-jawed at the number of seven- and eight-figure checks pouring into groups with names like Crossroads and Americans for Prosperity.