Humphrey eventually withdraws all troops from Vietnam by the end of 1971. It as seen as a defeat for the U.S. by conservatives on both sides of the aisle. The decision causes Humphrey's Commerce Secretary John Connally to resign in protest. Connally considers challenging Humphrey in the primaries but is dissuaded by Lyndon Johnson from doing so. Johnson convinces Connally to instead run for senate against John Tower in 1972 and then run for president in 1976. The biggest and lasting accomplishment for President Humphrey between 1969-1973 is the expansion of the Medicare program to cover all U.S. citizens which he signs into law in 1970 and the appointments of Arthur Goldberg as Chief Justice of the Supreme Court and Gerald Heaney and Shirley Hufstedler as associate justices giving the court a solid liberal tilt through most of the rest of the 20th century.
Meanwhile the Goldwater and Rockefeller factions in the Republican Party continue to battle it out after Nixon's loss to Humphrey in 1968. Nixon quietly retires to his home in California after another close election loss. The Republicans do well in the 1970 midterms and pick up seats in congress and governorships. But not enough seats to win a majority in either chamber of congress. Reagan is re-elected in California while Michigan Governor George Romney decides not to run for a third term in 1970 to focus on rehabilitating his image for a run for president in 1972. New York Governor Nelson Rockefeller is also making moves for a 3rd run for the White House in 1972 as polls show that President Humphrey looks vulnerable in 1972.
Humphrey's pro-civil rights agenda and exit from Vietnam also creates divides in the Democratic Party as well. Southern Democrats push for George Wallace to challenge Humphrey in the primaries. But President Humphrey choice for DNC Chair (Larry O'Brien) did not support the idea of creating a commission to evaluate the presidential nominating process (butterflying the McGovern-Fraser Commission). With Humphrey as president and the leader of the party it was easier for him to quell rumblings about the nominating process and keep the old McCarthy and RFK supporters satisfied with a withdrawal from Vietnam before 1972. But Humphrey's civil rights platform and support of desegregation continued to anger southerners. George Wallace made moves to run against Humphrey, but the party bosses and union leaders in the northeast and Midwest made it clear they wouldn't support him over President Humphrey in a primary race. Humphrey tried to keep southern Democrats happy with social programs and infrastructure projects (sending federal government dollars to the south). But the anger over civil rights looked like it was too much for HHH to overcome.
The 1972 Republican primaries featured Nelson Rockefeller, Ronald Reagan with George Romney as the top 3 contenders. While Rockefeller and Reagan fiercely battled each other in primary after primary, it became clear as the convention approached that if the party didn't heal this rift between the conservatives and the moderates and liberals, they'd be too fractured to beat Humphrey and would lose the presidency for the 4th election in a row. The 3 top contenders entered the convention in July with no candidate having enough delegates to win a majority on the first ballot. Reagan led in the delegate count, but clearly wasn't going to win on the first ballot. Which caused fear among Reagan (Goldwater) supporters that Romney supporters would then decide to move to Rockefeller on the 2nd ballot and give Rockefeller the nomination. Romney put himself in the position as a compromise candidate and lobbied both Reagan and Rockefeller supporters to support him. Rockefeller supporters feared that Romney was secretly working with Reagan on a deal where Romney would drop out, endorse Reagan and Reagan would pick Romney to be his vice-president. Romney was able to convince enough Reagan and Rockefeller supporters to endorse him as a compromise. Rockefeller seeing his own path was narrowing got some private concessions from Romney and the day before the nominating vote at the Republican Convention, Rockefeller released his delegates and endorsed Romney. The vast majority of Rockefeller's delegates voted for Romney giving Romney enough delegates to narrowly defeat Reagan for the nomination on the first ballot. To appeal to the conservative wing of the party, Romney chose Barry Goldwater's friend and fellow Arizona senator Paul Fannin to be his running mate.
Wallace seeing that he wouldn't defeat Humphrey in the primaries or on the floor at the convention, he decides to run as an independent again. With Wallace on the ballot in the general election he takes attention away from Romney and votes away from both Humphrey and Romney making 1972's race to look like another close one like 1968. After all the votes are counted the 1972 presidential election results look like this...
The 1972 Election Electoral College (270 electoral votes needed to win)
Pres. Hubert Humphrey/Vice-Pres. Edmund Muskie - 265 (Democratic)
Gov. George Romney/Sen. Paul Fannin - 189 (Republican)
Gov. George Wallace/Lt. Gov. Lester Maddox - 84 (American Independent)
After no nominee received enough votes to win the electoral college, supporters of President Humphrey and Governor Romney both lobby southern electors pledged to Wallace to vote for their guy. Humphrey only needs 5 faithless electors to get to 270. Humphrey doesn't want to leave it up to a congressional delegation knowing that in order to appeal to southern Democrats, he'd have to make serious concessions on civil rights in a second term. It is left to a congressional delegation in the incoming 93rd United States Congress to select the president. After the 1972 elections the delegations in congress looks like this in OTL:
24 - Democratic: (AL, AR, CA, FL, GA, HI, KY, LA, MA, MS, MO, NJ, NY, NC, OK, PA, RI, SC, TX, UT, WA, WI, WV, WY)
17 - Republicans: (AK, AZ, CO, DE, ID, IL, IN, KS, MI, NE, NV, NH, ND, OH, TN, VA, VT)
9 - Splits: (CT, Iowa, Maine, Minnesota, Montana, Maryland, New Mexico, Oregon, South Dakota)
President Humphrey is forced to make concessions on to the Democratic delegations in Wallace states on future judicial nominations, federal appointments, civil rights legislation, and support for more federal aide to southern congressional districts in order to cobble together the 26 votes needed to win the presidency for another 4 years. With the Democrats still in control of the senate, Vice-President Muskie is re-elected vice-president.
The economy takes a downturn in late 1973 and questionable concessions made to southern legislators causes journalist to investigate some of the concessions made by President Humphrey to secure the presidency. The bad economy and negative press attention the Humphrey administration receives for most of 1974 causes the Republicans to finally win a slim majority in the House of Representatives while the Democrats barley hold on to the senate. Gerald Ford becomes Speaker of the House in 1975. The loss of the House makes Humphrey in to a lame duck and his final 2 years is focused mostly on fighting House Republican investigations into the concessions he made to the southern Democrats after the 72 election. With his domestic agenda stalled, Humphrey continues to try to work on an arms control agreement with the Soviet Union which he does get and signs the SALT agreement in 1976.
Reagan was the clear front runner for the 1976 Republican nomination working to coalesce support in the Republican Party as far back as 1973. Vice-President Muskie and Texas Senator John Connally battled for the Democratic nomination which would become memorable for their fiery televised debates on the campaign trail. Muskie would prevail but the sagging economy would be too much for the Muskie and the party to overcome leading to Reagan comfortably winning the the presidency in 1976. The Republicans would also win a majority in both chambers of congress. Humphrey who is secretly battling terminal cancer again retires to Minnesota handing over power to Reagan.
Through the late 1970s the country would continue to to suffer from economic stagnation and an energy crisis. Despite a Republican majority in congress President Reagan would battle with Democrats and moderate Republicans over proposed budget cuts. With a small majority in the House, Speaker Ford was not a strong supporter of the kind of drastic budget cuts Reagan wanted to make. Especially not during a time of rising inflation and high unemployment. Reagan is able push through his tax cuts and budget cuts, but they do little to stimulate the stagnant economy or relieve the pain the public feels. The Democrats paint Reagan as the second coming of Herbert Hoover in 1978 and the recent death of former President Humphrey causes there to be a nostalgic outlook of the Humphrey years, less than two years since he left office. Republicans lose control of congress after the 1978 midterms. With the economy still in a deep recession and high unemployment, the 1980 presidential election results in Senator Joe Biden defeating President Reagan.