Specifically, members of Chavez’s ruling party claim that Capriles is responsible for prisoner abuse that occurred at a jail in Chacao, one of Caracas’s mayoral districts within the state of Miranda. On May 3, the day that Capriles announced his candidacy, Congresswoman Cilia Flores played a video of inmates at the jailhouse being beaten by guards. Never mind how tenuous the accusation is, the notion that a governor is directly responsible for behavior of prison guards. Never mind that Flores and her fellow legislators took this specific occasion (the announcement of Capriles’s presidential bid) to decry the conditions of Venezuelan prisons. (I visited a Venezuelan prison last year on the outskirts of Caracas, and I can scarcely imagine a day that a human rights violation doesn’t occur there. Stray dogs wandered in and out of the prison. Jail cells lacked locks. Food for inmates was often scarce. Violence, I was told, was rampant.) And never mind that the mayor of Chacao has subsequently said that the abuse captured in this video occurred before Capriles was even governor.

Despite the seriousness of the accusation, we can discount this episode for the most part. Because, to some degree, there is nothing remarkable about one political party trying to smear an opponent. It is, after all, politics. Yes, you would hope that the charges have merit before they are leveled. Yes, it is odd that the government would launch its broadside the day that Capriles makes his announcement. But no matter. Dirty politics is an unfortunate part of democratic politics.

We could ignore it . . . if that was all that Henrique Capriles had to worry about. But it isn’t. The bigger worry is whether he will even be allowed to stand for office. In Venezuela, hundreds of members of the opposition have simply been disqualified from competing in elections. One of the most notable examples is Leopoldo Lopez, a popular former mayor of Chacao. In 2008, he and hundreds of others abruptly learned that theycould not compete in regional elections later that year. They had not been found guilty of any crime. There had been no court order. Indeed, there was no due process at all, including an opportunity to appeal. The Comptroller General, an official loyal to Chavez, simply decreed it. By executive fiat, they were finished. There is nothing democratic about this practice, which is why it is most often found in countries such as Belarus and Iran.

The danger for Capriles is that he is clearly one of the more formidable challengers for President Chavez. (Hence, the need to try to smear him so quickly.) Despite the central government’s attempts to hamstring his ability to administer the state of Miranda, Capriles still polls extremely well, and his numbers place him well above other opposition candidates. After his first year as governor, I spoke with Capriles about the risks of running for office against Chavez. We met at a rally he held a couple hours outside of Caracas. “It’s good to have many leaders,” he told me, “because he will annihilate that one leader.”

That logic made sense in 2009, with presidential elections still several years away. But now with the big contest approaching and Chavez going into campaign mode, Capriles probably believed it was time to take his chances. As the front-runner to oppose Chavez, he is “that one leader.”

But he has no illusions. Trying to defeat an authoritarian leader at the ballot box is never easy, if they even let you run at all.