Polling -- and political conventional wisdom -- suggest that Sen. Thad Cochran will lose the Mississippi Republican runoff today to Chris McDaniel. (Worth noting: Both polling and conventional wisdom can be wrong.) Given that reality, I was astounded when I came across a Cochran ad savaging McDaniel -- to great effect -- that never ran on television during the race.

Let's look at the ad.

The spot details a number of impolitic -- to say the least -- statements made by McDaniel while he was hosting a radio show called "The Right Side" in the mid 2000s. (BuzzFeed's Andrew Kaczynski did yeoman's work uncovering some of the radio broadcasts, although Cochran allies warn there are hundreds of  hours of McDaniel tapes that have yet to be released.)

In the ad, McDaniel talks about a woman running for office because of her breasts (this actually happened), uses the phrase "Mamasita" and talks about crack.  After each comment, a female narrator intones "That's Chris McDaniel." The ad ends with McDaniel yelling, "I'm not done ... I'm not done," followed by the narrator saying:  "Chris McDaniel, you are done."

Is it tough? Yes. Very. But, remember that Cochran is a 36-year Senate incumbent who finished behind a state senator  June 3 despite the fact that the final weeks of the race were dominated by the arrests of McDaniel supporters who had secretly taped the senator's infirm wife in a long-term care facility. Cochran needed to change the dynamic of the contest -- from one centered on whether he had been in Washington too long to one focused on how McDaniel represented a major risk for Republicans hoping to hold the seat this fall.  What better way to do just that than this ad?

And, yet, this ad never ran one time on television. It was released by the Cochran campaign  June 14 in a targeted online buy to coincide with former Rep. Ron Paul's trip to the state to endorse McDaniel.

I did some poking around as to why the ad never saw the light of day. First of all, it was ready to run pre-primary. But then the nursing home story broke -- and Cochran devoted his paid media resources to highlighting that story. There was a concern that an ad like this one would be drowned out amid all of the attention focused on the nursing home story. Fair -- and probably right. (I also think there was probably some trepidation from Cochran to run such a hard-hitting ad. But politics ain't beanbag.)

But that doesn't explain why the ad wasn't run post-primary and pre-runoff.  By the time the primary happened three weeks ago, the nursing home story was fading.  Cochran could have easily launched this spot as part of a three week campaign to convince Republicans that McDaniel was just too big a risk to take. Would that message have worked? Maybe or maybe not. But it seems like it would have at least as good  a chance of working as what Cochran decided to do: 1) Focus on all he can do for the state in his senior position in Congress and 2) Try to convince Democrats to vote for him today.

As I said above, Cochran may well win today -- and his side is expressing considerable confidence that he will -- which would make him (and his strategists) right and me wrong. (Wouldn't be the first time!) But  if he does lose, my guess is his campaign will look back at this ad and wonder why they didn't run it early and often during the runoff campaign.