City Councilman Rolando Caicedo Arroyo would like to be mayor of Buenaventura, Colombia, someday. He is young, bright, and amiable; he says all the right things when you ask him about his priorities for this impoverished coastal town. In other words, he has all the characteristics that should allow him to get elected. But he seems skeptical of his chances. "Mayors, here in Buenaventura and many places in Colombia, usually receive patronage from drug trafficking," he told me. "Whoever has the most money wins. ...They buy the political support."

When Colombians go to the polls this month, some 24,000 politicians like Caicedo will be gaming for seats as town councilmen, mayors, and governors. They will not be the only ones trying to win, however. Narcotics-trafficking criminal gangs, known here as bacrim (bandas criminales, or "criminal gangs"), will also be contesting for influence through the local politicians they back. In order to win or maintain control over drug-trafficking routes, the armed bands are buying, intimidating, and assassinating their way into power.

Already, hundreds of hopeful candidates have been disqualified for having criminal records or links to armed groups. First, the country's intelligence service announced in July that some 400 candidates had criminal records. Days later, an Interior Ministry-funded investigation bumped that number up to more than 500. On August 1, the Conservative Party -- one of the three largest parties in the country -- said that it was expelling 480 of its own potential candidates from its electoral list for past criminal offenses or dubious links to illicit groups. And just this week, the mayor of Colombia's second city, Medellin, accused a candidate of criminal ties. He released photos of the man in poor company to prove his point.

Political violence has also been alarming. According to the Mission for Electoral Observation (MOE), a Colombian NGO, by mid September, 46 candidates or political leaders had been assassinated by an assortment of armed groups. And although the specific motives are often a mystery, the cases largely comes down to this: The candidates that get in the way of criminal activities, particularly at a local level, do not last long.

All this marks an incredible uptick in political violence, which for the past decade had been on the decline. Colombia's fight against organized crime is in flux; the traditional actors in the conflict, leftist guerrillas, who contested the state, and right-wing paramilitaries, who co-opted government institutions in response, have been respectively dilapidated and disarmed. As welcome news as this may be, it also means that all bets are off in the criminal world over who will control Colombia's lucrative cocaine exports. Whichever armed groups win control of local territory and influence would be able to consolidate their gains in the coming months and years. "[The armed groups] want to take land," said León Valencia, whose NGO, Nuevo Arco Iris, has worked with the Interior Ministry on its investigation. "They have interests in drug trafficking. They want to capture the resources of the state. And they're expending all the force in the world."

And, there are more actors than ever vying for influence with whatever means they can. After a decade of three-way conflict among a leftist guerrilla force, the Revolutionary Armed Forces of Colombia; the ring-wing paramilitary forces born to fight them; and a military intent on dismantling all criminal networks, armed groups have only proliferated across Colombia. The military effort diminished the once almost armylike FARC to a small terrorist network. Now, a new set of bacrim gangs, with names such as the Rastrojos, the Urabeños, and the Paisas, has cropped up in the vacuum left by FARC's demise, capturing illicit trade routes. Every one of these groups will try to "win" the elections in its own way.

Between 1964 and 2006, criminal groups had fought hard to influence Colombian elections -- both overtly, through violence, and implicitly, with cash. In the territories that they controlled, the guerrillas used the threat of violence to keep voters from going to the polls. Until they were demobilized, the country's paramilitaries, which cropped up locally in the 1990s to counter the influence of the leftist FARC but who quickly became just as dependent upon crime, preferred infiltrating political parties. In 2003, at the height of the paramilitaries' influence, an incredible 9 governors, 251 mayors, and 4,000 city councilmen were believed to have been elected with their help.

This year, however, was supposed to be different. Presidential elections last year saw remarkably little violence, as did a local vote in 2007 -- promising signs that the era of armed politics was ending. And recently, the state prosecutor opened more than 300 investigations into former links between officials and paramilitary groups, ending the impunity that such crimes had enjoyed. A new political reform law passed in July was also meant to help, holding parties accountable for candidates found to have illicit connections, regulating campaign contributions, and introducing a biometric voting system.

Despite these moves, however, monitoring groups, including the International Crisis Group, are sounding the alarm about criminal infiltration in the upcoming vote. The Ministry of Defense is so concerned that last March it started deploying extra troops to more than 100 at-risk municipalities. By the time the official campaigning started in August, the military believed that almost 16 percent of the country's municipalities are either at high or extremely high risk of violence and criminal activity.

The violence is increasing now because the stakes in controlling the illicit drug trade are higher than ever. Bacrim groups are eager to capture market share from the dismantled paramilitary networks, and they know that capturing government offices is the most reliable way to ensure their access to the trade.

"In some regions, [bacrim groups] will be happy with low-level connections -- basically, to secure their own impunity and to have access to information on law-enforcement activities, for example," Silke Pfeiffer, an analyst at the International Crisis Group, told me. "In others, they will be interested [in] and able to capture public resources. They need to have connections that go beyond just getting information -- they need to influence political decision making."

Just how hard the groups will fight depends on the geography of the conflict. As drug-smuggling routes have shifted from the Atlantic to the Pacific coasts of Colombia, so have reports of electoral tampering, violence, and intimidation. That is the case in Valle del Cauca, the district that is home to Buenaventura on the Pacific Coast, says Alejandra Barrios, the director of MOE. Bacrim groups are ruthlessly fighting neighborhood by neighborhood to secure access to the sea, where illicit products are exported. Another violent district, Antioquia, is suffering from the fallout of years of paramilitary demobilization and heavy FARC presence. In Arauca, it is unclear who is doing the harassing of candidates and civil society leaders, but it is clear why they are doing it: The district sits on most of Colombia's oil reserves.

In all these areas, honest candidates and other community leaders are at risk as targets of assassination attempts, harassment, and kidnapping. With 24,000 candidates, there are simply too many people for the military to protect. Not only that, but in Buenaventura, for example, police service protection can be more of a liability than a help. Armed gangs see police entering their territory as a provocation, one that can be attributed to the candidate or local leader whom law enforcement is guarding. The candidate is likely at greater risk of assault or assassination, not less, if he/she is seen to be working with the police.

For its part, the government is painfully aware of the threat of infiltration -- and the possibility that years of security policies aimed at curbing organized crime and the drug trade will come to naught. Should new bacrim groups win influence this month, the elections could easily set the stage for another round in Colombia's four-decade-long conflict. And this one might be harder for the government to fight. Unlike the FARC and paramilitary groups, the bacrim have no ideological agenda; they are focused solely on the drug trade, ruling out any possibility of negotiations, demobilization, or other political end to the conflict.

Hoping to head off violence before people go to the polls, the government is bumping up security measures countrywide. The Interior Ministry's investigations into candidates have already gone far in eliminating some of the most overt bacrim-politician connections. The ministry should also help run background checks for all the political parties, which undertake their own screening checks but, in the past, have been overwhelmed by the number of candidates to investigate -- an estimated 10,000 to 17,000 per political bloc.

Laws in the books in Bogotá, however, may not be enough to change what goes on in Colombia's periphery, where votes have in been routinely bought and sold. Voting is still a transaction in many parts of the country. "People believe, My vote has a value, and you have to pay for it somehow," Barrio said. Often, it is the armed gangs who have the money to pay that price on behalf of their chosen candidates.

Fearing that government efforts will not be able to stop these practices, civic organizations are doing their best to fight back against the threat of criminal infiltration. MOE has turned to Ushahidi, a Web platform that charts electoral violations from reports sent via cell phone or e-mail. All the information people send in is shared with government authorities, which can follow up with investigations if necessary. Community organizations in Buenaventura are also working to build up support for independent candidates in the classic democratic way -- without paying or intimidating citizens for votes.

Still, Colombia is bracing itself. When I asked Arroyo if he is worried about more violence in the run up to the election, he looked at me as if I should already know the answer. "We are in Colombia." So far, his prediction has been right; the rate of new electoral violations more than quadrupled as soon as official campaigning began a month and a half ago.

If violence continues to ratchet up before or during the voting, security forces will likely continue to boost their presence in vulnerable areas. They will almost certainly be able to keep a lid on attacks that would derail the elections or embarrass the country internationally. But what the military and police may not be able to stop is the quiet infiltration happening behind the scenes: intimidated voters who cast their ballots based on fear (or a price), campaigns funded with illicit wealth, and unhealthy friendships between criminals and candidates. Such ominous connections may remain secret -- even after the new mayors, city councilmen, and governors are already at the helm.