In 2010, John Hickenlooper was on top of the political world. He was cruising to a win in the governor's race running as a sort of un-politician who, among other things, hated negative ads.  He even ran a great ad in which he pledged to never run negative commercials -- while in the shower.

Fast forward four years. Hickenlooper, beset by his controversial decision to push a gun control package into law among other things, finds himself in a closer-than-expected race against former Rep. Bob Beauprez (R). And yet, he is still sticking to his no negative ads pledge. Nora Caplan-Bricker, in a terrific Hickenlooper profile for National Journal, hit on how the governor's promise not to go negative is coming back to bite him:

Choose a party, choose an ideology, choose a winning wedge issue—Hickenlooper stubbornly resists all that. Which brings him, this fall, to an uncomfortable pass: Having long ago repudiated negative ads, how does he counter the hits from Republicans? His response to the RGA ad was a clue to his strategy—and, for Democrats, not a promising one. In place of parachutes and showers, the spot that aired in September shows Hickenlooper waiting tables at the Wynkoop, repeating the same business maxims he has spouted his whole career. "First, money's always tight, so you make do with less," the voice-over says as Hickenlooper tallies a bill behind the bar. "And there's no profit in making enemies. It's why I don't do negative ads." The script is nearly identical to the talking points he used when he first ran for mayor in 2003—a message more befitting a political outsider than a man who's held office for more than a decade.

Hickenlooper is far from the only politician whose refusal to run negative ads is having -- wait for it -- negative consequences. In the South Dakota Senate race, former Gov. Mike Rounds (R) has refused to go negative and watched as the race has gone from a sure thing for him to something well short of that. "I'm not changing my approach," Rounds told the Sioux Falls Argus Leader two years ago at the start of his Senate bid. "I know there's more money involved in it and there's more outside groups that have an interest in it, but I'm going to do my best to maintain the integrity of a good, solid, appropriate race for people in South Dakota."

In each case, Hickenlooper and Rounds learned the wrong lessons from their past races.  Hickenlooper walked into office in 2010 because the Republican party imploded and former GOP Rep. Tom Tancredo ran as a third party candidate. Hickenlooper had the luxury of running positive spots -- like the "shower" ad -- because there was no one on the other side making a well-funded or consistent case against him. Ditto Rounds who won a Republican primary for governor in 2002 because his two better-known and better-funded primary foes savaged one another on TV while totally ignoring him.

The lesson for both men? People love me. I don't NEED to run negative ads because, well, people love me -- and they always will.

That is, of course, one of the most common follies of modern politics -- the assumption that timing, coincidence or even luck are all less important than sheer force of personality when it comes to persuading people to vote for you. Hickenlooper and Rounds are coming face to face with the reality that what happened in 2010 or 2002 has almost no bearing on what will happen in 2014.  Campaigns are about choices. And when you are running against an opponent or an opponent's party who has the money and the willingness to make a negative case against you, not responding in kind is asking to lose.

It's possible that Rounds and Hickenlooper would rather lose on their own terms than break their no negative ads pledge to win. But, ask yourself this: What's a better to see your vision for government realized? To serve as Senator or Governor  -- even if you have to run negative ads to get there -- or to lose but remain loyal to your positive-ads-only principle?

The best politicians tend to be pragmatists, grasping the fact that there is no one-size-fits-all approach to the politics of politics. The best recent example of that flexibility? Barack Obama, reversing himself on accepting public financing for the presidential election because he knew doing so would provide him a massive spending edge (and an increased likelihood of winning) over John McCain in 2008.

Political situations change. Voters who love you one year may hate you (or be ready to hate you) two or four years later. Politicians who box themselves in by making no negative ad promises in perpetuity reveal how little of that political reality they understand.