Origin of the Species

AND THE WHEEL TURNED AGAIN.

This time there was no violent break. It happened in fits and starts. Democrat Woodrow Wilson, elected in 1912, thanks to the GOP crackup, was no Abraham Lincoln -- his presidency was a hodgepodge, and so was his party. This was not entirely his fault; some blame lay with William Jennings Bryan, the previous leader of the Democratic Party, who pinned the party's hopes on populism. This small-town, Bible Belt movement was mainly about money -- the populists wanted more money in circulation -- but it also attracted a lot of prims to the Democrats and left the party deeply divided over Prohibition.

But much of the problem was attributable to Wilson. Though he billed himself as a progressive, he was a caveman on racial issues, and, politically speaking, he had all the warmth, appeal and deal-making skills of cold tripe. Wilson's uneven leadership ceded the 1920s to GOP presidents, but this was a false noon for the Taftian conservatives. When the Great Depression hit, the Republicans were a disaster, and Democrats regained the upper hand in U.S. politics. Now the parties had crumbled and reformed themselves to such an extent that they had almost entirely swapped coalitions.

The New Deal Democrats of 1932 chose from the menu of enduring American either/ors: big government, high taxes, populist, frisky and French. But the trauma of the Depression was so intense that Franklin Roosevelt was to able to bring both Northern and Southern voters into the same coalition -- under an anti-big business banner. He was able to hold progressives and fundamentalists in a single uneasy alliance by delivering the balm of government assistance. FDR gave working people the right to unionize and to have unemployment insurance and worker's compensation. But he also managed to hold on to moderate business leaders by saying he was saving them from the far worse fate of socialism. No president ever enjoyed more or stranger bedfellows.

It was the old familiar cycle: At first, the party's coalition produced success upon success. The Depression was ended. Fascism was defeated. Union wages and the GI Bill helped produce a robust middle class. Social Security eased the fear of growing old. A war-worn Western Europe coalesced behind U.S. leadership to form the world's most prosperous alliance.

But this burst of big-government reform changed the American agenda, and with it the balance of interests in the Democratic Party. For example, many of the farmers and working people who embraced the New Deal as an answer to the Dust Bowl and the bread line were shocked to find themselves, when good times returned, in the company of cocktail swillers, pacifists, beatniks, feminists and hippies.

More important, once the crises of the 1930s and 1940s were past, the country found itself face-to-face with the long-festering issue of racial discrimination. Without the Depression or war to hold the Democrats together, it was no longer possible to accommodate both segregationists and liberals. In 1948, the young mayor of Minneapolis, Hubert Humphrey, grabbed the Democratic convention and tugged it to embrace civil rights. When that happened, an angry group of Southern Democrats bolted from the party and nominated South Carolina's governor, Strom Thurmond, to run for president as a protest.

The complete breakup of the New Deal coalition took time, but by 1964, Thurmond had left the Democratic Party altogether, and over the next 20 years, millions of Southerners followed him. Segregation died, thankfully, as a legitimate issue, but resentment of Washington, D.C., endured. When Republican Ronald Reagan came along in the 1980s, preaching that "government is not a solution to our problem, government is the problem," he achieved an electoral college landslide to match FDR's victory in 1936. Old Dixie was transformed into a stronghold for the party of Lincoln.

AFTER TWO CENTURIES of assembling coalitions, watching them split, then scrambling after the pieces like children under a pinata, our parties have arrived at this moment topsy-turvy. The Republicans have morphed into the party of low taxes and limited government, the party of Reagan, pushing an agenda that is conservative both fiscally and morally -- low tax and very prim -- but more assertive internationally than at many times in its past.

And it seems to have worked. In recent years, the GOP has enjoyed higher levels of party identification -- that is, more people say they are Republicans -- than at any time in the history of the Gallup Poll; Republicans are even with the Democrats. Their party controls the White House and Congress and a majority of state legislatures.

Is this the start of a long reign? Or is the GOP on the brink of getting too big? If you listen closely to the internal arguments of America's Republicans, you can hear a lot of strain between the prims, with their morality-setting agenda, and the segment of small-government voters that prefers to be left alone. Even within the small-government congregation there is tension between the low-taxers and the budget-balancers.

Call me a wacky optimist, but I like to think both parties will continue, somehow, to screw themselves up on a regular basis. I hope so, because if you take the long view, it's a pretty good thing we have going here. Partisan invective aside, our system is strong enough to be relatively stable, yet weak enough not to do the sort of catastrophic damage we've seen from tyrannies around the world.

Unlike Alexander Hamilton, Thomas Jefferson lived long enough to see that the partisanship of their youth meant little compared with the values that endure: concord, trust and mutual respect. In his retirement years, Jefferson renewed his friendship with Federalist John Adams. The old rifts were repaired as the two men traded warm and wise letters, reflecting on all that had happened since they had worked together on the Declaration of Independence. In one of those unbelievable strokes by history's screenwriter, Adams died in Massachusetts precisely 50 years after he had signed that crucial document. It was July 4, 1826. They say his last words were, "Thomas Jefferson lives." The spirit was correct, though the words were wrong, for Jefferson had died that same morning in Virginia.

"We acted in perfect harmony thro' a long and perilous contest for our liberty and independence," Jefferson wrote to Adams in 1813. "A constitution has been acquired which, tho' neither of us think perfect, yet both consider as competent to render our fellow-citizens the happiest and the securest on whom the sun has ever shone. If we do not think exactly alike as to its imperfections, it matters little to our country which, after devoting to it long lives of disinterested labor, we have delivered over to our successors in life, who will be able to take care of it, and of themselves."

If we do not think exactly alike . . . it matters little. Such brilliance! It reminds me of one more thing to be said in favor of our much-maligned parties. Now and then, they produce such leaders. Not as often as we would like, surely. But, so far, often enough.

David Von Drehle is a Magazine staff writer. He will be fielding questions and comments about this article at 1 p.m. Monday on washingtonpost.com/liveonline.