Jimmy Carter ran for Governor of Georgia in 1966 (I think) and lost, which put him into a depression, from which he eventually became a born again Christian.
The negative side-effect was that in addition to having too little experience running things (four years as GA governor), Carter didn't have the ruthless legislative skills of someone like LBJ.
But let's assume that he wins the Governorship in 1966. He pursues center-of-the road policies to benefit all Georgians, and is liberal in regards to civil rights. He's the first in a comming wave of "new southern" governors--progressives who try to heal the racial divide and move forward with common sense legislation. He will be followed by men such as Rueben Askew of Florida, William Jefferson Clinton of Arkansas, ect. ect.
Carter's efforts to bring about peace and understanding strikes a chord with the people of his state. Even as the rest of the country seems to be tearing itself to peices over Vietnam and race, Georgia remains oddly calm. National Democratic leaders begin to take a hard look at Carter for a potential WH run.
Nixon wins in 1968 and is reelected in 1972, as IOTL...however, Watergate still happens.
Carter, who's had since 1966 to get the hang of legislation (he knows how to twist arms when he needs to) is eyeing the White House. The country seems to be entering a malaise, in his eyes, and America needs a dynamic leader to restore its luster.
Carter declares early and wins the Iowa Caucusus (as IOTL) but isn't known as "Jimmy Who?" since he's gotton favorable national press for his policies in Georgia. He gets the Democratic nod, and chooses Washington State's legendary Henry M. "Scoop" Jackson as his Veep, a former competitor. Jackson is a hawk regarding the Cold War, and he helps to boost Carter's national security credentials.
Carter campaigns hard, and wins a convincing victory over Gerry Ford (sweeping the South and winning several Rocky Mountain states thanks to Jackson).
Once in office, Carter moves quickly to deal with the mess left over from the Nixon/Ford years. He immediently moves to control inflation (and the deficit) through a mixture of de-regulation (of some government monopolies), and cutting middle class taxes.
He also pushes through the Energy Independence Act of 1977, which heightens millage requirements for American cars and invests heavily in alternative energies. Carter and Jackson announce their intentions for a "Second Manhattan Project" to acheive alternative fuels. The Departments of Energy and Education are inaugerated at this time.
The Energy Independence Act also calls for tougher inspections of America's nuclear plants. One such inspection at Three Mile Island, PA in September 1977 catches a glitch in the plant that could have caused a disaster.
In 1977, in an effort to improve race relations even further, Carter goes on his now legendary Southern Listening Tour, where he gives multiple speeches at college campuses, churches, and state legislatures on what must be done to facilitate love and friendship over the ugliness of the past. The Tour is a huge success, and Carter gains even more positive press over it.
The Carter Administration also adopts economic sanctions against the Apartheid regime in South Africa for their refusal to release Nelson Mandela, and for their refusal to dismantle Apartheid; several right-wingers angrilly denounce him for this move, most notably Jerry Falwell, Pat Buchanan, and House Minority Whip Richard Cheney of Wyoming.
Carter acheives a great victory on the international stage through negotiating a peace treaty between Anwar Sadat and Menacham Begin in 1978.
Carter's bid to control inflation causes a recession this year, in which the Republicans make gains (one of their more notable victories is in Texas, where George Walker Bush beats Kent Hance for a House seat). The Democrats still maintain control of Congress, however, and the GOP is dissapointed at not making more gains (Carter is still personally popular).
By 1979, inflation is starting to go under control.
Also this year, Rezah Pahlavi, the Shah of Iran, is disposed in the Islamic Revolution; however, under pressure from Jackson, who dislikes the Shah's autocratic policies, Carter declines to let him into the United States.
The US Embassy is largely left alone, save for the usual protests.
By 1980, Carter has erased the scandal and economic doubt of the Nixon/Ford years, and enjoys high personal approval ratings.
However, he faces a daunting challenge from Ronald Reagan, the former actor-turned governor. Reagan, who has a vast wit and charisma, threatens to make the election close.
In the end, the rapidly improving economy, and Carter's tough stand against the Soviet invasion of Afghanistan (and through boycotting the Moscow Olympics) turns the election in his favor. Carter uses his genteel charm (mastered through all those session of the Georgia legislature) and easy going nature to match Reagan's self-depracating wit. Reagan, attempts to turn their one presidential debate in his favor by going "There you go again...." after Carter defends his energy record with a wealth of clear information. Carter's legendary reply seals the deal with voters. "Yes sir, Ronnie, there I go again. In my second term, we're going to be investing in our own people, our own technology, and our own future. I don't see how Knute Rockne could oppose that." That garners a chuckle even from Reagan, while the rest of the crowd bursts out laughing. The election is now almost over. Carter wins an even more impressive victory than in 1976, taking all of the South, and most of the Midwest, all of the Border States, and keeping Colorado, Washington, and Hawaii in his pocket out west.
Round Two of the Carter Years is about to begin.