It’s either good investigative journalism or a nefarious “black campaign.”

Whether true or false, Mexico state Gov. Enrique Peña Nieto has been knocked for a loop by a YouTube video that purports to show him as a regular customer of a posh Beverly Hills boutique.

Peña Nieto is far ahead in the polls for 2012 presidential elections, and riding out front makes him an easy target, as this scandal shows.

The video popped up on YouTube earlier this week. It shows the House of Bijan, perhaps Beverly Hills’ most exclusive men’s shop, displaying a wall clock with Peña Nieto’s name on it. The clock is alongside others who are purportedly clients of Bijan, including the Prince of Wales, King Juan Carlos of Spain, Mexican billionaire Carlos Slim and dozens of others.

Peña Nieto’s opponents immediately started bashing him, saying earning a clock on the wall of Bijan is only for those who spend between $2 and $5 million there.

Here’s what Education Secretary Alonso Lujambio (and potential campaign rival) posted on his Twitter account: "Peña Nieto: explain to Mexicans where you got the 23 million pesos to buy clothing in the most expensive store in the world.”

Peña Nieto late this week addressed the controversy multiple times. He said he’d never been to Bijan at 420 Rodeo Drive and called the video a “black campaign.” 

Later, he said such tactics could even threaten the federal government’s relations with state governments and put “at risk institutional relations.” 

Peña Nieto makes an easy target on the personal wealth front. He comes from rather humble stock and has never worked outside government for any significant period. So this scandal feeds the perception of elected officials lining their pockets at the public trough. Moreover, he is from the Institutional Revolutionary Party, the former authoritarian party that ruled Mexico as a fiefdom for seven decades.

But imagine for a second that Peña Nieto is right and that he’s never been to the Beverly Hills boutique. Then this augurs for some below-the-belt politicking during the upcoming campaign. Many Mexicans would throw in last weekend’s arrest of Jorge Hank Rhon, the PRIista who is a former Tijuana mayor, as part of election politics. Hank Rhon was charged with firearms violations because soldiers found 88 weapons in his house. With extraordinary speed, prosecutors said Friday ballistics tests show two of those weapons were used in homicides in Baja California. This kind of prosecutorial celerity is uncommon in the extreme in Mexico.

I would expect Peña Nieto’s camp to dish out its own surprises soon.