April 1, 1947: President Harry Truman gets word of the Taft-Hartley Act while it is in committee. He contacts Lyndon Johnson (a Representative from Texas) to organize a meeting with several House Democrats and tells them in no uncertain terms that he will veto the act. He has a similar discussion with several Democratic Senators later that day.
April 17, 1947: After weeks of debate on the House Floor, the Taft-Hartley Act passes by 288-127. Among those for the bill were Representatives Nixon and Johnson - whose unexpected turn against President Truman endeared him to the conservative wing of the party.
April 18, 1947: Harry Truman has a rather intense private meeting with Representative Johnson, informing him "if this is the hill I die on, so be it". This stance trickles out to the rest of the Congressional Democrats and will later feature in a few political ads.
May 13, 1947: The Taft-Hartley Act passes the Senate 62-30, to the disappointment of President Truman.
May 14, 1947: The Taft-Hartley Act is vetoed the moment it hits President Truman's desk, returned to the House with a strong message from President Truman.
July 12, 1948: "As it has been made clear to me that I do not have the support of the Democratic Party, I hereby renounce my candidacy for President" - Harry Truman after an exhausting few years of dealing with a more and more obstructionist Congress (frustratingly including his own party) decides that he will not seek re-election. Multiple candidates pop up as potential replacements, including war hero James Roosevelt and popular conservative Democrat Lyndon Johnson.
July 14, 1948: Eventually the Democratic Party agrees on James Roosevelt as their candidate for President. Son of a President, War Hero, Movie Star, and with little political baggage (unlike Truman) Roosevelt appears to be a good candidate for President. The only concern is his lack of direct political experience, but the Democrats are sure that they can guide him.
November 20, 1948: James Roosevelt narrowly beats Dewey and becomes the 34th President of the United States.
November 20, 1952: James Roosevelt loses to Earl Warren, the latter becoming the 35th President of the United States. This happened because of discontent over Roosevelt's perceived incompetence in actually running a country (reasonable since he is a political newbie).