One Roosevelt, Red Roosevelt
Before we get to the next big switch, at little aside about a failed attempt to shift the two-party system: Teddy Roosevelt and his Progressive party. Having ascended to the presidency due to William McKinley's assassination, and then having won the 1904 election, he felt the honorable thing to do (and TR considered himself to be a paragon of honor) was to count that as his two terms and, as was tradition (but not, at the time, law), follow in Washington's footsteps by not seeking a third term. William Howard Taft took the nomination, and was easily elected.
But then the trouble started. Roosevelt found Taft to be unacceptable in office, and pressed for the party nomination in 1912. But he was rebuked by Taft's supporters; humiliated and unwilling to compromise, Roosevelt and his supporters walked out, and formed their own party, the Progressive or Bull Moose party. The new party seemed to survive solely by Roosevelt's force of personality, and had little if any appeal for staunch Democrats, and none for any Taft-supporting Republicans. At this point, Republicans were enjoying a rather solid and comfortable 55/45 or better advantage in Presidential elections; but the Progressives split the party almost completely down the middle. The final popular vote totals were 27.4% for Roosevelt and 23.2% for Taft; a total of more than 50%, but individually, both lost to the Democrats and Woodrow Wilson's 41.8%, and by an absolute landslide in the electoral college: 88 for Roosevelt, to 8 for Taft, to 435 for Wilson.
Roosevelt apparently learned his lesson though; in 1916, when the Progressive party nominated him again, he declined, and endorsed the Republican candidate; Wilson won reelection, but only narrowly. But Roosevelt's contrition placated his party well enough that he was the front runner for the 1920 nomination; cut short only by a quick but fatal illness.
The lesson from this aside should be obvious: if all you do is split your party, you'll both lose. Neither the Republicans nor the Progressives got any appreciable support from Democratic voters. To succeed, a third party needs to divide, and then build from the pieces, a coalition from both (or as we saw in part I, the only) existing major parties. And it's not enough to build "in the middle", as Roosevelt tried; you have to be completely outside the axis of partisan identification.
Two Roosevelt, Blue Roosevelt
On to today's transition, from the fourth party system to the fifth. Economic recessions had helped usher in the previous realignment, by instigating the Populist party and the silver faction of the Democrats. And economics would play in a big way for this one as well. Yes, we're talking about the Great Depression. But there's not a whole lot to say. When the stock market crashed in 1929, Herbert Hoover insisted that he and the Republicans had it under control; but three years later, not many believed him. Instead, the put their trust in Franklin Delano Roosevelt (Teddy's 5th cousin.)
So, there's that option: hope that unbelievable economic devastation will be wrought upon the nation, and that you'll be there to pick up the pieces. Not a particularly uplifting or proactive strategy (at least I hope no one would try to cause such a thing), but one that we've seen can work.
It's also important to note that this shift didn't involve the rise of any new party (not even an analog to the aborted Populist party), only a drastic shift in support from one major party (which had dominated national politics for decades) to the other. Third parties did enjoy a startling increase in support after the crash, but not enough to even act as spoilers. Was it because of the homogenizing effect of modern communications, making what would have been strong regional third-party movements into a more diffuse national movement? Was it FDR himself, something about him that drew would-be third-party supporters to the Democrats? Or perhaps we had simply become more savvy about the inevitability of a two-party system under our spoiler-prone voting system?
Whatever it was, like the voters Bryan had brought (and driven from) the Democrats at the turn of the century, the voters FDR brought also stuck around; the New Deal Coalition, were reliable not just for FDR, but for Democrats in many elections to follow, up until the late 1960s; which may (or may not have, depending which historians you ask) have represented another realignment of the party system. But we'll discuss that next time.