I never imagined Scott Walker as president. But that doesn't necessarily mean he couldn't have won.

Now Walker has decided to drop out. But if he really wants to be president, then why on Earth would he do such a thing?

Yes, his poll numbers are down, and his fundraising has dried up. He has made too many gaffes, and his debate performances have been lackluster. Well, so what?

No, I'm not kidding. This is September 2015. The Iowa caucuses will be held on Feb. 1, 2016. Anything could happen by then.

Rick Santorum managed to win Iowa in 2012 with a total campaign budget that was probably less than what the Walker campaign spends on toner. Bobby Jindal's poll numbers are hovering around the margin of error, and he's still around.

Trump is riding high in the polls, and has drawn most of his support from Walker, but that's the point — the smart money still has to be (for the love of God) that the Trump candidacy will deflate at some point, which will leave all those voters up for grabs. The field has to clear at some point, and a solid showing in Iowa would have brought those flighty donors back.

At the end of the day, Walker is still a conservative Republican who won three elections in a row in a blue state, including the only incumbent victory in the entire history of gubernatorial recall elections in the United States. He passed union-busting bills, a concealed carry law, and a 20-week abortion ban. Nothing is like running for president of the United States, but he knows something about campaigning for office and winning elections. No matter how you slice it, he is still a credible presidential candidate.

This is a lesson about politics, especially at the highest level. Sometimes, the top prize only goes to those who never give up, who have an all-commanding faith in themselves. At this point in the 1992 cycle, Bill Clinton was stuck in the single digits, with a couple sex scandals on top of having no money. And he was running to be president in an election in which nobody thought the Democrats had a chance anyway.

And that's the point: Nobody has more grit, when it comes to fighting political fights, than Bill Clinton. And he won most of them Rocky-style, simply through sheer obstinacy, sheer refusal to quit (remember that impeachment business?). In France, Jacques Chirac, who ran for president three times — including a humiliating loss the second time, which led him to be written off by the media/money/political class — is a similar character. Those politicians are the ones who win, because they have a fire in the belly, a special thing deep within their guts, that makes them bite onto destiny and not let go.

There's no reason Scott Walker couldn't have been one of those politicians.

Except that, apparently, he isn't.