I've met Mr. Carter and been to his sunday school class (which he's now been teaching for 25 years) a few times. I lived about 10 miles away from him for several years. Our country only has two major parties with several mini-parties inside of them, but if the United States had a Social Democratic party like many European countries, or maybe even a Christian Socialist party, Carter would be a member of it.
First of all, a little background: Carter is from Southwest Georgia, Sumter County. Due to the aftereffects of the Civil War, he grew up in the Depression around NO Republicans. Nearly everyone who lived during the Depression is a fan of FDR. During that time, the perception was that capitalism had failed, and Christian socialism (in the form of the social gospel movement- what would jesus do?-) flourished.
Some major religoius-left related events took place during Carter's formative years. In the first half of the 20th century, a Baptist minister named Clarence Jordan started a farm in Sumter County, in which black and white citizens would work together and live communally. White supremacists were pissed: they called for a boycott, shot at them while driving by, and even bombed a feed store in downtown Americus for doing business with them. Carter also survived a boycott by the White Citizens Council during this time. Koinonia Farm still exists today, and Carter no doubt regards them as heroes. (My church was also founded by Koinonians. The farm website is here:
http://www.koinoniapartners.org )
Before he died, Clarence Jordan and a millionaire named Millard Fuller (who had left Alabama, dispensed his wealth, and moved to Koinonia to save his marriage) founded what became Habitat for Humanity. Who promoted this organization, enabling it to become a worldwide entity? Jimmy Carter.
Meanwhile, the Civil Rights Movement grew stronger, and Martin Luther King, Jr. was jailed in Southwest Georgia. Despite the White Citizens' Council boycott, Carter was elected to the school board. Later, with the help of Dr. Harold Isaacs (who has since founded the association of Third World Studies and retired) Carter was elected governor by saying things that segregationists wanted to hear. He shocked them when he entered office, put up pictures of MLK (the most famous Christian socialist to date) and declared that segregation was irrelevant and the era of the "New South" had begun.
Carter was elected President in 1976 thanks to a huge populist campaign (documented in books by Harold Isaacs) in which citizens of Sumter County went North and handed out peanuts door to door. He was the last Democratic president to pull the New Deal coalition together and benefit from a Solid South.
As president, he created the department of Education, gave aid to the new Sandinista government (read: Christian socialists), emphasized human rights in his foreign policy, and negotiated a couple of famous treaties. He wanted to implement Universal Health Care, as Canada had in the previous decade, but was unsuccessful due to the Iran hostage crisis, etc.
Still, after his presidency he has promoted the growth of democracy (every country that has embraced democracy has also usually embraced some form of socialism) and the expansion of Habitat for Humanity. His most recent book "Our Endangered Values..." is basically a treatise in line with other famous evangelical socialists (Jim Wallis, for example.)
Hope I've made my case,
DB