...It's HERE AND NOW. So how is today's government shutdown shaping up historically, even as it's just beginning? In 1995 and '96, the government shut down twice, for 26 days total. That was the longest shutdown in history. But there have been more than a dozen since the '70s. There was the shutdown of 1976 during a budget debate been President Ford and a Democratic Congress.

There was a 12-day shutdown in '77, under President Jimmy Carter. It focused on abortion funding. There was a shutdown in 1981 after President Reagan deadlocked with Democrats over tax cuts. So when did shutdowns become a political tool, and how is today's shutdown different, if it is?

Julian Zelizer is professor of history and public affairs at Princeton's Woodrow Wilson School. He joins us from their studios. Julian, first of all, tell us, because we're mentioning '95, '96, '71. We're also hearing people say that this is the first time this has happened in 80 years. So what distinctions are people making?

JULIAN ZELIZER: I think a short history would be that until 1980, you did have government shutdowns, including the one under President Ford. They were usually about specific spending issues. The government would continue to function. After 1980, when the Carter administration makes a ruling that government workers could not come into work in these conditions, the potential of a shutdown becomes more severe.

You continue to have battles, but they're usually just for a few days. They're skirmishes, primarily symbolic. And then it's in '95 and '96 when you have the first serious shutdown, combined with workers not going to work, where I think we enter into the period that we're currently still living under....