Nearly four decades ago, the delivery of a suitcase stuffed with $250,000 in cash to one of then-President Richard Nixon's top aides helped fuel the Watergate scandal and a complete overhaul of the laws regulating campaign finance. Voters in the 2012 election are likely to know less about who is trying to influence their decision than they have at any time since then. And, compared to the amounts of unregulated dollars flowing into campaigns, the stash of cash that former Commerce Secretary Maurice Stans accepted during the 1972 presidential campaign seems like peanuts.

Here's a look at ...