Candidate to Lead Mexico Is Shot : Presidency: Ruling party’s Luis Donaldo Colosio is hit in head and chest after Tijuana speech. Crowd surges around and detains two suspected assailants.

Two gunmen stepped from a crowd Wednesday and shot and seriously wounded Luis Donaldo Colosio, the presidential candidate of Mexico’s ruling party who was campaigning in a poor area of this border city, authorities said.

Details of the condition of Colosio--who is 44 and was widely expected to be elected president of Mexico during national elections scheduled for Aug. 21--were not immediately available.

But he reportedly suffered wounds to the head and chest and was taken from the scene bleeding profusely. Mexican radio carried urgent appeals for a rare blood type for transfusion.

Colosio was rushed to Tijuana’s General Hospital, but reports indicated that he was to be transported via helicopter to nearby UC San Diego Medical Center.

The candidate was shot after a campaign speech in the neighborhood of Lomas Taurinas, near Tijuana’s international airport.

The furious Tijuana crowd, estimated at 3,000 people, surged around his apparent assailants, beating them and detaining them, according to broadcast reports.

Their identities were not immediately available, but television broadcasts from the chaotic scene showed the alleged assailants as mustachioed men who appeared to be in their 20s. One of the men appeared bloodied and disheveled as a gun-wielding man--possibly a security guard who was trying to ward off further attacks on the assailant--battled members of the crowd.

Wednesday’s attack promised to create further turmoil for Mexico’s Institutional Revolutionary Party or PRI, as it is known.

The party, which has ruled Mexico for more than six decades, was badly embarrassed earlier this year by an Indian uprising in the southern state of Chiapas that left at least 145 people dead. Rebel leaders are now considering details of a tentative peace accord.

Colosio’s shooting stunned Mexico, a nation of 92 million that had hardly recovered from the shock of the New Year’s Day rebellion in Chiapas.

His shooting came one day after Manuel Camacho Solis, the government peace envoy in Chiapas, announced that he would not run for president.

The prospective candidacy of Camacho Solis--Colosio’s chief rival within the PRI--had threatened to split the ruling party since January.

Tension about August’s elections has been mounting steadily since the insurrection in Chiapas. The rebels have called for broad national reform toward true democracy, and President Carlos Salinas de Gortari has pledged reforms in the electoral process.

Mexican lawmakers are considering a broad package of reforms. Among other things, the proposed changes would make electoral authorities more independent of the PRI and other parties, stiffen penalties for voter fraud and modify the ballots to prevent ballot-stuffing.

Colosio, an amiable politician whose open manner contrasted with the stiff persona of many Mexican lawmakers, has been controversial ever since he was named as the party’s candidate Nov. 28.

Salinas, exercising a longstanding prerogative of Mexican presidents, personally chose Colosio--one of his longtime proteges--as his successor, passing over Camacho Solis and other rivals.

Critics complained that Colosio’s adherence to free trade and other policies too closely mimicked the neo-liberal economic blueprint of Salinas. Since the Chiapas rebellion, Colosio--a native of the border state of Sonora--had been distancing himself somewhat from Salinas’ economic plans, stressing the need to help the great numbers of poverty-stricken Mexicans.

But Colosio has long had many defenders within the structure of the PRI, which has been synonymous with government here since its founding in 1929. Party stalwarts favored him for the presidency, confident that he would do nothing to erode the PRI’s longtime dominance.

Before being named the PRI’s presidential candidate, Colosio headed Mexico’s vast Social Development secretariat, which included a multibillion-dollar anti-poverty initiative called Solidarity.

In the wake of the Chiapas rebellion, many criticized Solidarity as a program that did little to resolve the pressing problems of rural and urban poverty that still characterize Mexico.

Colosio had served as a PRI senator and chairman of the national party. An economist, Colosio is a native of Magdalena del Kino, near the Arizona border. He did postgraduate work at the University of Pennsylvania and in Austria.

In Washington, State Department spokesman Mike McCurry said the United States was “horrified by this brutal assassination attempt.”

“We very much hope that he is able to recover fully from this attack and resume his distinguished career,” McCurry said.