I'll have to read up on that.
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The election results produced a change dramatic enough that many analysts saw them as indicative of a broad Republican realignment. The GOP gained 55 House seats and 12 Senate seats, enough to give them control of both houses of Congress for the first time since the elections of 1928. Furthermore, liberals bore the brunt of the losses. Democrats outside the South lost in excess of 40 percent of their seats, while Southern Democrats suffered no losses. In the states, Republicans gained three governorships, not a large number but enough to give them a majority of governorships. Richard Nixon was first elected to the House, and Thomas Dewey won a handsome reelection as Governor of New York, giving an additional boost to his presidential ambitions. Truman was so thoroughly damaged by the election results that Democratic Senator William Fulbright of Arkansas suggested that the President was a spent force. According to Fulbright, Truman should appoint a Republican Secretary of State and then resign his office, an act which, by the succession law of the time, would have made the new Secretary of State the next president.
Instead, of course, Truman made a legendary comeback. Subsequently, the Republican 80th Congress has become famous as the foil against which Truman ran his successful reelection campaign of 1948, a campaign that also brought renewed Democratic majorities in the House and Senate. Indeed, Truman made much hay criticizing what he called the "do-nothing 80th Congress," and it is tempting to view the Congress elected in the 1946 midterm as a fundamentally irrelevant blip in American history.
However, in reality, the 80th Congress was highly accomplished, bearing legislative responsibility for the following:
Congressional approval of the 22nd Amendment limiting the president to two terms;
Passage of the Taft-Hartley Act that allowed states to adopt "right-to-work" rules, drove communists out of the labor movement, and generally established balance between labor and business in labor law;
Passage of a major tax cut;
Pressuring Truman into ending wartime economic regimentation;
Enactment of the National Security Act of 1947, which established the U.S. Air Force, the Department of Defense, the National Security Council and National Security Advisor, and the Central Intelligence Agency;
Approval of the Marshall Plan and aid to Greece and Turkey, the starting point of the policy of containment;
Most of these innovations have endured more-or-less intact to this day.
Consequently, the elections of 1946 helped reelect Harry Truman in two ways. Most obviously, Truman was able to force a number of confrontations with the 80th Congress that strengthened his image as a "fighter for the people." Less obviously, but at least as important, Truman was saved by the 80th Congress from being dragged down by public fears of high taxation, overly-strong unions, and over-centralization of power. The Republican Congress might be said to have cleared the road for Truman’s reelection by forcefully removing the issues that most endangered it.
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http://www.ashbrook.org/publicat/oped/busch/06/1946.html