Presidential nominee who was most unlike his predecessor

[Orser67]

Which presidential nominees were most unlike the people who were nominated by their party four years prior? I'm primarily talking about political stances, but background, appearance, etc. could be interesting to talk about as well.

Grover Cleveland and Williams Jennings Bryan seem to fit the bill pretty well.

[FEMA Camp Administrator]

That seems like one of the best bets. Other examples could be McKinley vs. Teddy Roosevelt and John W. Davis vs. Al Smith.

[I Will Not Be Wrong]

George McGovern and Jimmy Carter
Gerald Ford and Ronald Reagan
Barry Goldwater and Richard Nixon
Michael Dukakis and Bill Clinton

[BaconBacon96]

McGovern and Carter first come to mind, as do John W. Davis/Al Smith, Ford/Reagan and Cleveland/Bryan.

[Randy Bobandy]

Michael Dukakis and Bill Clinton

Remember the keynote speaker at the 1988 Democratic National Convention?

[True Federalist (진정한 연방 주의자)]

McGovern and Carter first come to mind, as do John W. Davis/Al Smith, Ford/Reagan and Cleveland/Bryan.

Ah yes, Bryan and Cleveland.  They remind me of that song Burls Ives song "Silver & Gold" from Rudolph the Red-Nosed Reindeer.

[I Will Not Be Wrong]

Michael Dukakis and Bill Clinton

Remember the keynote speaker at the 1988 Democratic National Convention?

That was a terrible day for Clinton.

[Randy Bobandy]

Michael Dukakis and Bill Clinton

Remember the keynote speaker at the 1988 Democratic National Convention?

That was a terrible day for Clinton.

Murphy's law was alive and well for Willie that day.

[The Mikado]

Breckenridge and McClellan (who, whatever he was, was not a Southern supremacist)?

Seymour to (no candidate) for the Democrats between 1868-1872 is an obvious choice.

[SWE]

Bryan/Cleveland is definitely the most obvious. John W. Davis was a pretty big contrast too both Cox and Smith too.

[FEMA Camp Administrator]

Cleveland-Bryan-Parker-Bryan is a pretty good string.

[Cassius]

Reagan and Bush I were definitely a pretty sharp contrast when it came to their political styles and personalities (as well as their political history). Jackson and van Buren is another good one in my opinion (rugged, western, populist war veteran known for his fiery temper vs short, smartly turned out New Yorker who definitely wasn't a populist).

[Oswald Acted Alone, You Kook]

Dole and Bush? They're pretty dissimilar. At least for the modern cases.

[Mordecai]

Surprised no one mentioned JFK and LBJ.

[Meursault]

George McGovern and Jimmy Carter

McGovern and Carter first come to mind

These two were closer than they might appear. McGovern proposed pardoning Vietnam draft dodgers; Carter did it. And both were devout Christians, even if they came from different denominations.