Young people today might have difficulty with this: at one time in America, the two main political parties shared similarities, and actually showed civility to one another.

As the late, great Lou Reed once sang, “Those were different times.”

Steven Levitsky and Daniel Ziblatt, in their book How Democracies Die, describe an America in which many conservatives actually voted Democratic, and many liberals actually voted Republican. The conservative South voted solidly Democrat, a tradition that dated to Reconstruction. And the urban Northeast was populated by fiscal conservatives, many of whom were fairly liberal on social issues. (My dad was one of them.) And—hard to believe, now—but white evangelical Protestants actually leaned Democratic.

This era encompassed 100 years of American history. But there was a dirty caveat to this calm bipartisanship: African-Americans were excluded from the democratic process.

With the passage of the 1964 Civil Rights Act and 1965 Voting Rights Act, which brought black citizens into that process, a sea change occurred in American politics. Previously, heterogeneity characterized both parties. Whereas they divided on the issues of taxes, federal spending, government regulation, and unions, they did agree on race. But with these two Congressional acts, the Democratic Party became the party of civil rights, while the Republican Party became the party of a white status quo.

“In the decades that followed, southern white migration to the Republican Party quickened. The racial appeals of Nixon’s “Southern strategy” and, later on, Ronald Reagan’s coded messages about race communicated to voters that the GOP was the home for white racial conservatives.”

And while this was occurring, blacks (and, later, other minority groups) not surprisingly supported the party that emphasized human rights.

This is significant, because “for the first time in nearly a century, partisanship and ideology converged.” (The bold type is mine.) Today, the two parties are divided not only by policy, but they also represent, as How Democracies Die aptly displays, “different communities, cultures, and values.” This polarization was exacerbated by religion, especially after the Supreme Court’s 1973 Roe v. Wade decision legalizing abortion, and Ronald Reagan’s outreach in the 1980s to the so-called “Moral Majority”: white Christians opposed to legalized abortion, gay marriage (later), and who advocated school prayer.

How Democracies Die says that this ideological separation occurs in other Western nations, such as Britain, Germany, and Sweden. However, these nations don’t have parties exhibiting the same hostility as in the U.S. Part of this may be due to America’s long history of only two major parties, so the “anger” is less diffused. But that doesn’t explain all of it.

Levitsky and Ziblatt note that, while both parties have shifted closer to the fringes, this polarization has been “asymmetric, moving the Republican Party more sharply to the right than it has moved Democrats to the left.” They cite a 1964 essay by historian Richard Hofstadter that discusses “status anxiety,” which occurs “when groups’ social status, identity, and sense of belonging are perceived to be under existential threat. This leads to a style of politics that is ’overheated, oversuspicious, overaggressive, grandiose, and apocalyptic.’” The authors conclude that Hofstadter’s essay is far more relevant today than when it was written.

What is the “existential threat”? It is the changing demographic landscape in America. Blacks, Latinos, gays, non-Christians, and other once- disenfranchised groups (most of whom vote Democratic) are growing, and Christian Caucasians (most of whom vote Republican) see their numbers slipping.

The authors cite many events and trends since the Nixon administration’s “Enemies List” and illegal wiretaps—the latter condemned and punished via bipartisan gatekeeping—that indicate with clarity why political “mutual toleration” and “institutional forbearance” (recall that these are the unwritten rules, or the glue that binds democracies) have become obsolete. I’ll highlight a few of them:

Newt Gingrich: the former GOP Speaker of the House began his Congressional career in 1978 in Georgia with a “cutthroat vision of politics” that “questioned his Democratic rivals’ patriotism.” His team actually distributed memos to Republican candidates encouraging them to use pejorative descriptors to characterize their Democratic opponents, such as “pathetic, sick, bizarre, betray, anti-flag, anti-family, and traitors.” Gingrich encouraged a no-compromise style of political hardball, and “was one of the first Republicans to exploit” severe polarization as a political tactic.

Filibuster abuse: before the 1970s, the annual number of filibuster attempts never exceeded seven, but “by 1993-94, the number had reached eighty,” under a GOP minority in Congress hostile to the presidency of Bill Clinton.

Clinton hostility: “Senate Republicans…pushed aggressively for investigations into a series of dubious scandals, most notably a Clinton 1980s land deal in Arkansas (the so-called Whitewater investigation).” They followed this by appointing independent counsel Kenneth Starr to investigate. When Gingrich became Speaker in a GOP landslide in 1994, the party “adopted a ‘no compromise’ approach—a signal of ideological purity to the party base—that brazenly rejected forbearance in pursuit of victory by ‘any means necessary.’” This bore fruit with a five-day government shutdown in 1995; a 21-day government shutdown in 1996; and reached its “apogee” with the impeachment of Bill Clinton in December 1998 for lying to a grand jury about extramarital sex. It was a strictly partisan maneuver by a Republican House to bring down Clinton.

“In an act without precedent in U.S. history, House Republicans had politicized the impeachment process, downgrading it…to ‘just another weapon in the partisan wars.’”

Tom DeLay: Gingrich left Congress in 1999, but his brutal style of no-compromise politics was inherited by a Texan, House Majority Leader Tom DeLay. DeLay “shared Gingrich’s partisan ruthlessness,” packing lobbying firms “with Republican operatives” (the K Street Project) and starting a “pay-to-play system that rewarded lobbyists with legislation based on their support for GOP officeholders.”

Levitsky and Ziblatt accuse DeLay of carrying “routine norm breaking into the twenty-first century.”  Longitudes accuses him of idiocy, based on statements like “God wrote the Constitution.”

(I’ll pick up with the 21^st century next time…there’s sadly much more, starting with the explosion of propagandistic conservative media outlets that began during the Clinton years.)