[1][3] Loeb began his career as a teacher of the French and Spanish languages at the Townsend Harris High School.

[3][6] In 1941, with Reinhold Niebuhr he co-founded the Union for Democratic Action (UDA), which he served as executive director.

[1][2][3] In 1948, ADA tried to recruit (then) General Dwight D. Eisenhower to run for president as a Democrat, which came about "in a very peculiar way."

He had Jack Kroll of the CIO Political Action Committee (CIO-PAC) ask ADA to serve as indirect conduit and recruit Eisenhower through his younger brother, Milton S.

[2] In the 1948 presidential election, Loeb believed that a combination of Truman's strong civil rights platform plus his de facto center, thanks to walk-outs on the Democratic Party by Strom Thurmond's Dixiecrats and Henry A. Wallace's Progressives gave the American people an easy choice.

[1][2][3] In 1953, he became part-owner and co-publisher with Roger Tubby of The Adirondac Daily Enterprise of Saranac Lake, New York, which he continued through to 1970.

[1] He died age 83 of pneumonia on January 10, 1992, the Alice Peck Day Extended Care Facility in Lebanon, New Hampshire, after suffering from Alzheimer's disease.