Kai Ryssdal: Ask anybody who says they know anything about poltitics, and if they say, yeah, they thought the Republican presidential nomination would indeed take this long to wrap up, they're probably lyin' to you. If things work out as Mitt Romney hopes, today's Wisconsin primary could be the real beginning of the end of the Santorum candidacy.

This year's primary campaign has been longer than anybody thought. More expensive, too.

Allan Lichtman is a professor of history at American University. Good to have you with us.

Allan Lichtman: Thank you.

Ryssdal: There is -- in American political history -- a division, right? There's a before-primaries and after-primaries timeline?

Lichtman: That's right. In fact, there's a double division. You know, primaries were first introduced in the early 20th century. The first great primary struggle was that between Teddy Roosevelt and his handpicked successor as president, William Howard Taft, with whom he was very disappointed. Teddy Roosevelt won the primaries, but wasn't nominated because in those days, even though there were primaries, most delegates were selected by the party bosses. You then get the second shift in the 1970s when the parties abandoned behind-the-scenes delegate selection and all delegates now have to be selected in either open primaries or open caucuses. Exit the old line party bosses.

Ryssdal: Is that when this whole process that has now become the super PAC sort of started? Is that when money really became the issue?

Lichtman: Money really did begin to become the issue with the adoption of caucuses and primaries because you now had to win by amassing delegates, and you had to campaign all over the country, including in very large states. And you couldn't do that without large sums of money.

Ryssdal: What about super PACs, then? As we move into what I guess you can call a post-primary environment in this election cycle, are they going to be as influential as they've been the past six, eight months?

Lichtman: They won't be quite as influential in the general election because the candidates will be lavishly well-funded, that they'll be less dependent on super PACs than the Republican candidates have been in the primary elections when they found it pretty difficult to raise a lot of money unto themselves.

Ryssdal: So you believe Mitt Romney's going to have an easier time raising money as he moves towards becoming the nominee?

Lichtman: Mitt Romney will have a much easier time raising money as he becomes more inevitable as the Republican nominee, because those interests that want to defeat Barack Obama will then coalesce around him, and those interest have an awful lot of money.

Ryssdal: Does the same thing then apply for the president? I mean, he's had his own troubles with raising super PAC money and there's been a lot of talk about how he might behind in the dollar chase. Is he going to have more success raising money once there's an opponent named?

Lichtman: Absolutely. Once there's an opponent named, and once this race is sharpened up, the Obama money-raising machine will go into full gear. The amount of money raised by presidential candidates has just asymptotically increased in recent years. It's doubled and doubled and doubled again.

Ryssdal: Kind of amazing, though -- we started talking about a time when it was, you know, old white guys in a smoke-filled room, and now here we are with the economics of politics.

Lichtman: Well that's right. The old white guys or any guys or women in a smoke-filled room don't count for anything anymore. You now have to get delegates the old-fashioned way -- you've got to earn them in primaries and caucuses.

Ryssdal: I was waiting for you to say, 'You've got to buy them.'

Lichtman: And you know what? Money helps.

Ryssdal: Allan Lichtman is a distinguished professor of history at American University in Washington, D.C. Professor, thanks a lot for your time.

Lichtman: Anytime. It was great fun.