KILLING ESCALATES MEXICO DRUG WAR

MEXICO CITY-A leading Mexican gubernatorial candidate was killed early
Monday in a state bordering Texas, in the highest-level assassination
of a politician here since President Felipe Calderon declared war on
drug cartels in 2006.

The killing of Rodolfo Torre, who was seen as a shoo-in for governor
in Tamaulipas, represents an escalation of the drug traffickers' war
against the Mexican state.

"This is an attack not only against one citizen, but against all
society; an attack not just on one politician, but against all
politicians and our political institutions," Mr. Calderon said in a
televised address.

Mr. Torre, of the Institutional Revolutionary Party (PRI), which
governed Mexico until 2000, and at least three others were killed when
his campaign convoy was ambushed by gunmen on a rural highway in
Tamaulipas state.

The candidate, his chief of staff, campaign chief and at least one
bodyguard died, officials said. Televised images showed several
bodies, covered in white sheets, laid out on the pavement near the
candidate's convoy of bullet-riddled SUV's. Mr. Torre and the others
are believed to have fled their cars during the attack, but didn't get
far.

Mr. Torre, a 46-year-old former doctor and father of three, was
leading opinion polls by an average of 20 percentage points for
elections on July 4. Twelve of Mexico's 30 states are due to elect new
governors and mayors on Sunday.

Although lower-level politicians have been killed by drug gangs, the
killing of a gubernatorial candidate is a sign that cartels are
increasingly willing to fight back against the government.

Mexico's warring cartels have killed 23,000 people since President
Calderon took power in December 2006 and sent some 45,000 army troops
and federal police to a handful of states to take on drug gangs.

The assassination was seen by many as evidence that Mexico could be
going down the same road as Colombia, where drug cartels challenged
the state through bombings and assassinations during the 1980s and
1990s in order to get the government to back off. Such a development
would increase political instability in a nation of 105 million that
shares a 2,000-mile border with the U.S. and is a top trade partner.

"This is a direct challenge to the Mexican state," said Ardelio
Vargas, a PRI deputy and head of the national defense committee in
Mexico's lower house. "This is an armed group trying to tell Mexicans
who we can and can't elect." Mexico's leading political parties vowed
to go ahead with Sunday's vote. There was no word of a replacement
candidate for the PRI.

The attack was Mexico's highest-profile political assassination since
1994, when Mexico was rocked by two killings, including that of PRI
presidential candidate Luis Donaldo Colosio by a lone gunman. The
killings weren't believed to be the work of drug cartels.

Officials said they had no clear idea why Mr. Torre was targeted.
Speculation by analysts and politicians centered on three theories:
Mr. Torre was an honest politician who posed a threat to drug gangs;
Mr. Torre had struck a deal to protect one gang and was killed by a
rival gang angry at being cut out; or a cartel killed him just to make
life more difficult for a rival gang that controls turf in the state.

Until now, the cartels have mostly been killing each other as they
battle for control of lucrative smuggling routes to send drugs to the
U.S., the world's biggest market for illegal drugs. Tamaulipas, for
instance, sits across the border from Texas and has three busy border
crossings-Nuevo Laredo, Reynosa, and Matamoros-where cartels can slip
drugs across undetected.

But in recent months, several cartels have made it increasingly clear
they won't consider the government itself off-limits. Under pressure
from tens of thousands of soldiers and federal police sent in by Mr.
Calderon, cartels have launched a greater number of attacks against
soldiers, police, and even politicians. They have also threatened and
killed reporters in several states, gagging much of the local press.

This year's state elections have proved particularly bloody. Last
month, gunmen burst into a house owned by mayoral candidate Jose Mario
Guajardo Varela of Mr. Calderon's National Action Party (PAN) in Valle
Hermoso, Tamaulipas, killing Mr. Guajardo, his son and an employee.
Earlier this month, bombs were thrown into the offices of the PAN and
Party of the Democratic Revolution (PRD) in Culiacan, Sinaloa.

In many of Tamaulipas's smaller cities, the PAN is asking of its
candidates not to campaign to avoid being exposed to possible attacks.
The PAN's gubernatorial candidate, Jose Julian Sacramento, said he
pulled his wife and daughter off the campaign trail for fear of their
safety.

Mr. Sacramento mourned the killing of his rival. "He was my friend,"
he told Televisa network. "We had agreed to have a clean campaign and
we were both focusing on the issues rather than personal attacks."

Organized crime hasn't only affected campaigns in the north. On May
25, the mayor of Cancun and PRD candidate for governor in Quintana Roo
state, Gregorio Sanchez, was arrested on charges of money laundering
and conspiring to traffic drugs. Mexican authorities said he had ties
to the Los Zetas cartel, which operates around Cancun. Mr. Sanchez
denies the charges.

The assassination of Mr. Torre added a deviation from the
violence-which until Monday had targeted parties opposing the PRI.

During the party's long rule over Mexico, the PRI was known for a
comfortable relationship with crime organizations, cutting political
deals and carving out territory for drug traffickers. After Mexico's
transition to democracy, the PRI took a less-tolerant stance to crime,
but still appeared to be a more welcome alternative to drug cartels
than Mr. Calderon's PAN.

But the dynamic in states dominated by PRI, such as Tamaulipas, has
changed due to shifting alliances in the drug underworld. Two
erstwhile allies, the Gulf and Zetas cartels, have fought a bloody
turf battle this year for control of Reynosa. Meanwhile, the Sinaloa
Cartel, run by kingpin Joaquin "El Chapo" Guzman, has also tried to
make headway in the state.

As a result, old alliances have fallen and politicians are stuck in
the middle. "Now you don't have a single cartel running the state,"
says George W. Grayson, a drugs expert and professor at the College of
William and Mary.

Some say the violence threatens to erode Mexico's democracy in
northern states. "The building of a political culture in which people
resist having their vote taken away is very fragile in the north,"
says Dan Lund, a pollster with Mexico City-based The Mund Group. "Now
it's been taken hostage by organized crime."

Laurence Iliff contributed to this article.