I may be the one person who listens to the election news and thinks about Benjamin Harrison. You don’t remember him? President of the United States from 1888-1892? The scion of a political dynasty that yielded enough failed presidencies to make the Harrisons the Bushes of the 19th century? So why do I think of Harrison? Because this is an election year that centers on money.

It is cynical to think that money is all that matters in American politics. But it is daft to think that money does not matter. It tempts incredulity to think that the more money in an election, the freer the speech and the more open the debate.

But following the money is always a good idea. It is best to pay attention when patterns of political spending shift. They have shifted in 2014, with vast amounts of money oozing into what would otherwise seem unlikely contests — judicial elections in North Carolina, state senate elections in Washington — as well as the more predictable contests for national office.

I think of Harrison and 1888 because money sharply shifted that year. The gradual expansion of the Pendleton Civil Service Reform Act had choked off the usual sources of campaign finance: kickbacks, contributions and unpaid service from officeholders who owed their positions to the party. The Republicans — Harrison’s party — needed new sources of cash.

GOP candidates were running on the protective tariff, so they turned to people who would benefit from higher tariff rates. One Republican official called on the party to “put the manufacturers of Pennsylvania under the fire and fry all the fat out of them.” And they did...