I go on conservative boards, and yes, many Conservatives feel he was the worst President of the 20th century, if not the worst of "all time." According to some I've talked to, even though they hate LBJ or FDR, those men had some merits as leaders and did at least some things right; They say Carter on the other hand was a guy totally in over his head and was a complete failure.
While I don't geel Carter was an all out evil guy or anything, I generally agree with that assessment. While I respect FDR's leadership abilities, the same way I respect TR's, Carter in my opinion was too naive for the Presidency and, as you said "in over hid head". LBJ I can't say too many positive things about, though.