The US elections in 1948 were a full sweep victory for the Democratic Party—the presidency and both houses—running on a strong pro-labor stance. Upon election, of course, Truman and the Democratic controlled congress turned against the unions, breaking them up and suppressing them and making sure they were led by people who fully supported the Korean “police action” (that was opposed by the majority of Americans, and the overwhelming majority of workers). The attacks on the union movement were continuous and powerful, although, in fairness to Truman, he never went as far as FDR, who pushed for a law permitting striking workers to be drafted into military service and forced to labor.
The primary technique Truman used in this was to raise hysteria against “Russian spies” and “Russian influence.” While it is worth discussing how the actions of the Stalinists in the 30s and 40s permitted this to work, that isn’t the point I’m making now. What I want to say is, this campaign was very successful, in that he was able, with the help of AFL and CIO bureaucrats, to break up some of the more militant unions and significantly weaken others. It is not going too far to say that Reagan was able to launch such a successful attack on the unions in the 1980s because of the action of Truman and the Democrats 30 years earlier.
In 1952, the Republican Party ran on a platform that the Democrats were “soft on Communism” and won the presidency and control of Congress and unleashed McCarthy.
In other words, “Hey, thanks for going out and finding that nice stick. Now we’re going to beat you to death with it.” When you abandon principle (not that the Democrats had any) for short-term political gain, you’re stropping the razor that will be used to cut your throat.
Here endeth the lesson.