But the arrest is unlikely to stem the ongoing violence that has caused frustrations to mount among Mexican voters ahead of the nation's 2012 presidential election. In fact, it's likely to have the opposite effect, says Sylvia Longmire, a former special agent with the U.S. Air Force Office of Special Investigations and author of the forthcoming book "Cartel: The Coming Invasion of Mexico's Drug Wars."

"It's a paradox: The more success Calderón has in either killing or capturing the heads of these cartels, the more potential there is for the cartels to fracture," Longmire told Trend Lines yesterday. "And the more they fracture, the more violence you're going to have."

The government campaign against La Familia over the past several years had already resulted in a split within the cartel's ranks, Longmire added. With El Chango now in custody, she explained, a power vacuum has opened, with the Los Zetas and Sinoloa cartels angling to take over La Familia's territory in the Michoacan and Guerrero states along Mexico's southwestern Pacific coastline.

"There are reports that, prior to his arrest, El Chango was trying to form an alliance with the Zetas on behalf of La Familia in order to keep La Familia's head above water," said Longmire. "So there's a possibility that because that was put in motion before he was captured, La Familia could now be absorbed by the Zetas."

The problem, she said, is that La Familia's territory also butts up against that of the Sinoloa Cartel, which might seize on El Chango's capture as an opportunity to carry out a hostile takeover of what is left of La Familia.

"The Sinoloa and the Zetas have been fighting for quite some time," Longmire explained. "So this would just up the stakes a bit."

Whatever unfolds during the coming weeks, it is likely to involve bloodshed and more of the violence that sparked major protests last month in Mexico City, where thousands took to the streets to voice frustration over a war that has claimed some 36,000 lives since Calderón launched it five years ago.

As noted by Trend Lines last month, chances are good that Calderón's National Action Party will be succeeded in next year's election by the opposition Institutional Revolutionary Party (PRI), which has a history of minimizing violence and disputes with the cartels by allowing them a degree of autonomy in parts of the country.

What remains to be seen is the extent to which the PRI might try to capitalize on the violence ahead of the elections by running on a platform of bringing back negotiations with the cartels.

"Because of how delicate the situation is, it's too early to tell," said Longmire. "I think many politicians are holding their breath to see what the pulse of the population is six months from now before coming out and saying this is how we're going to proceed toward the cartels."

Buying a measure of peace in Mexico by negotiating with the cartels, however, would create tensions in U.S.-Mexican relations. "If any future leader in Mexico capitulates to the cartels, it would represent a break from the way that the U.S. government has pursued its counterdrug policy for the last 50 years," said Longmire.

Sylvia Longmire's book examining the drug war in Mexico and its likely future trends is due for release in September.