If it was Obama versus Sanders, at end of 8-year Hillary presidency...

[Blue3]

If it was Obama versus Sanders for the 2016 Democratic nomination, at end of 8-year Hillary presidency in which Obama was either VP or Secretary of State the first 4 years...

what would this primary race look like?

[Dr. Arch]

If it was Obama versus Sanders for the 2016 Democratic nomination, at end of 8-year Hillary presidency in which Obama was either VP or Secretary of State the first 4 years...

what would this primary race look like?

I would guess like 2008 in 2016.

[IceSpear]

Probably similarly, but with Obama cutting into Bernie's lead among college kids and youngs in general.

[○∙◄☻¥tπ[╪AV┼cVê└]

Obama is obviously nowhere as terrible a person as Hillary. But I don't know if he'd be doing much better. Hillary already has most blacks, and Obama doesn't have the gender card, and wouldn't resort to race baiting attacks. Obama would certainly be doing better with college students than Hillary is. But Bernie would probably be doing better with poor people, women, and Hispanics.

[Famous Mortimer]

This situation wouldn't happen. Obama would be running to the left. Sanders wouldn't be running at all. If he was running, he would be polling Kucinich numbers because there would be other name candidates in the race, the field not having been cleared like it was for Clinton.

[Asian Nazi]

Impossible to guess.  A lot depends on what the political climate is like and how Obama is perceived.  Many of the factors that helped him in 2008 would not be present, but he is such a talented campaigner that I could see him pulling it off anyway.

[Stranger in a strange land]

Obama would still be widely seen as the next in line, whether he was serving as Senator from Illinois, Hillary's VP, or in the cabinet: even from his emergence on the national stage at the 2004 Democratic Convention, it was apparent that he was going to be on a national ticket someday. He would very likely be the front-runner. Sanders would be running a pure left-wing protest vote candidacy, if he was even running at all. Another thing to remember is that under a Hillary presidency, the Moderate/DLC Wing of the party would have more influence, so they would likely have a candidate in the race as well.

[tonyreyes89]

This situation wouldn't happen. Obama would be running to the left. Sanders wouldn't be running at all. If he was running, he would be polling Kucinich numbers because there would be other name candidates in the race, the field not having been cleared like it was for Clinton.

basically this. But to answer the OP it wouldn't be as close as irl because people actually like Obama

[Kingpoleon]

Bernie gets whites, Hispanics, Jews, labor, and old people(old people by five to eight points) while Obama gets African-Americans and "ethnic whites". Young people and libertarians would be the swing vote.

Also, polling:

Sanders: 30%
Obama: 29%
Heinrich: 25%
Webb: 10%
Undecided: 5%

Webb represents the Blue Dogs while Heinrich is the DLC-er running. Heinrich could be replaced by Booker, Hickenlooper, or O'Malley.

[Mr. Smith]

Hillary would have won Arkansas, Kentucky, Missouri, Montana, and Virginia in '08 against McCain, this would have changed the landscape a lot in 2010 and 2014, especially in the South.

Therefore the answer is N/A