Gubernatorial candidate David Vitter (R) and wife Wendy during his election night watch party in Kenner, La., on Saturday. The senator lost the race. (Max Becherer/AP)

Sen. David Vitter (R) lost his once-sure-thing bid for Louisiana's open governorship on Saturday largely because of the fact that he had admitted to being involved in a prostitution ring.

Makes sense, right? Usually politicians who acknowledge frequenting prostitutes don't get elected to things. Except that Vitter went public with his ties to the "D.C. Madam" way back in 2007. And, in 2010, he won reelection to the Senate by 19 points over a sitting Democratic member of Congress.

I wanted to know why Vitter's ties to prostitutes effectively ended his political career eight years after the incident but were seen as no big deal three years after it all happened. So I reached out to a bunch of Republicans and Democrats for answers to that question. The answers I got fell largely into four categories.

1.  Louisianans care much more about who their governor is than who their senator is. It might be hard for many in Washington to grasp, but Louisiana is far from alone in caring more about who its governor is than who goes to the Senate from the state. (New Jersey, California and Texas are three others that jump to mind.) "Voters have a higher standard for governor than someone they send off to Washington," said Bob Mann, a professor of mass communication at Louisiana State University who was a top aide to former senator John Breaux (D).

Added Curt Anderson, a Republican consultant who advises outgoing Louisiana Gov. Bobby Jindal: "In Louisiana, they take the governor's race seriously. They feel like they are voting for the head man for the state. They do not take Senate races very seriously. The job of a senator from Louisiana is to go to Washington and try to stop the madness in D.C. and oppose [President Obama] Obama. That's it. If you can do that, fine."  

Simply put: The bar that Vitter needed to clear was MUCH higher in the governor's race than in his 2010 Senate bid.  And he never really understood that or came close to clearing it.

2. Vitter had a real primary fight this time. In 2010, despite Vitter's obvious political weaknesses, he drew only nominal primary opposition. (Vitter won 88 percent of the vote in a three-way race.) That wasn't true in 2015.  Both Public Service Commissioner Scott Angelle and sitting lieutenant governor Jay Dardenne ran against Vitter in the open jungle primary. And they ran hard — making Vitter's prostitution admission a centerpiece of the primary race.

"Voters in 2010 were vaguely aware that Vitter's name had come up in the D.C. Madam case, [but] there were few details and virtually none knew that there was some kinky elements to it," said Charlie Cook, the head of the Cook Political Report, a nonpartisan campaign tip sheet, and a Louisiana native. "These hints started getting aired over the summer and gave it an entirely new dimension."

Here's one example — an ad funded by Gumbo PAC, a Democratic-aligned super PAC that played heavily in the race. The ad began airing right after the primary.

By the time the primary concluded Oct. 24, it was clear that Vitter was in deep trouble. He barely beat Angelle and Dardenne, and his 23 percent of the overall vote put him WAY behind state Rep. John Bel Edwards, who was largely unchallenged for the Democratic nod. And Edwards made sure that the damage done to Vitter in the primary wouldn't wear off by immediately launching this humdinger of an ad.

"The main reason [Vitter lost] is that John Bel was willing to push the issue in ads and debates," Breaux said. "Also his GOP opponents took the issue directly to Vitter. None of this was done before to this extent!!" (Dardenne endorsed Edwards in the runoff, while Angelle stayed out of the race entirely.)

3. Obama wasn't on the ballot. In case you missed the 2010 election cycle, it was a very good time to run as a Republican — particularly in a state such as Louisiana. The president Obama was at or close to his nadir in terms of public opinion. Being an "R" in that environment was often more than enough to win. Reining in Obama and keeping Democrats from a 60-vote super-majority was all that mattered. And, in a federal race — as opposed to a state one — Vitter was more able to effectively make the case that he would help block Obama's agenda while his opponent — former Rep. Charlie Melancon — would rubber-stamp that agenda.

Here's one ad that Vitter ran in that race; notice the "Charlie Melancon...still choosing Obama over us" kicker.

4. Edwards was conservative enough for the state. Edwards positioned himself as a pro-life, pro-gun military man. Not as a national Democrat. Check out this ad in which Edwards notes: "Louisiana's future doesn't belong to a political party. It belongs to all of us."

"If John Bel was not pro-life and pro-gun, there is no way he could have run," said Anderson, the consultant to Jindal. "Him being culturally conservative was the final nail in Vitter's coffin."