The campaign for president of Mexico has taken on the air of the bad old days, when the dictatorial PRI, the Institutional Revolutionary Party, loaded elections for its candidates. The top contender, Mayor Andrés Manuel López Obrador of Mexico City, is expected to be barred from the 2006 race by a transparently political indictment on charges of ordering the construction of a service road to a hospital after a judge said no. We don't endorse his actions, but Mexico's voters should be allowed to make their choice, not have it made for them.

Last week, a congressional panel voted along party lines to strip Mr. López of his immunity as an elected official. Congress's lower house is expected to take up the issue today and to confirm the decision. Then he'll probably be indicted - and by law, no one facing a criminal trial can run for president.

Mr. López has taken full advantage of the situation, which has distracted attention from serious charges of corruption against his top aides. He has compared himself to the Rev. Dr. Martin Luther King Jr. and vowed to campaign from jail. Certainly, he is no Martin Luther King. A longtime PRI official who moved to the leftist Democratic Revolutionary Party, he has built a machine in Mexico City modeled on the PRI nationwide. He is increasingly a demagogue, and he has fought reforms like making information available to the public. He responded to a huge march against a crime wave by calling it an attempt by dark forces to attack him.

But since the powerful can still get away with anything in Mexico, few people believe his opponents' pious claims that they are just trying to uphold the rule of law by indicting him. He may not be the right man for the presidency, but that issue should be for Mexico's electorate to decide.

••• 4/13/2005 12:11:00 PM •••