By JUAN FORERO
 
BOGOTÁ, Colombia, April 26 — Like practically all Colombians, the caller to a radio program the other day had a strong opinion about a bill that would permit President Álvaro Uribe to extend his time in office.

"Let the Colombian people decide," the man said in a familiar baritone, contending that the bill should become law and that Colombians should be allowed to re-elect him. "Don't stop the public from expressing itself."

That the caller to the show on RCN radio was Mr. Uribe himself points to a conundrum Colombia faces as Congress considers whether to amend the Constitution and permit him to run for a second term. On one hand, Mr. Uribe is immensely popular, with an approval rating approaching 80 percent. He would probably win another four-year term.

But Colombians are also asking whether a sitting president — even one admired for cracking down on Marxist rebels and propping up the economy — should lead an effort that would clearly benefit his own government.

"You do not change the rules of the game to benefit yourself," said Gustavo Petro, a congressman who opposes giving Mr. Uribe a second term.

Supporters say Mr. Uribe has suffused Colombia with hope, no small task in a country riven by relentless violence.

Political and other killings, kidnappings and attacks on villages are all down, as Mr. Uribe's so-called Democratic Security strategy of fighting rebels and setting up a government presence in isolated regions has taken hold. Aggressive eradication efforts are, at last, curtailing vast fields of coca, and the economy is expected to grow 4 percent this year.

"He's synchronized with the reality of the people," said Senator Óscar Iván Zuluaga, who is coordinating the support for re-election among lawmakers. "He confronts problems. He does not hide them. That is the secret of this president."

But the specter of the authoritarian man on horseback, which has bedeviled Latin governments for years, is never far from people's thoughts here. Opponents of giving Mr. Uribe another term say it would consolidate too much power in his hands, creating the kind of strong-armed rule that characterized Peru under another tough, antirebel crusader, Alberto K. Fujimori.

In the 1990's, with Peru facing a fanatical rebel group and hyperinflation, Mr. Fujimori dissolved Congress and changed the Constitution to win re-election. His 10-year presidency was marked by corruption and rights abuses, finally ending in disgrace when he fled into exile.

Other recent or current leaders — from Hugo Chávez in Venezuela to Carlos Menem in Argentina — extended their terms, leading to political polarization in Venezuela and rampant corruption in Argentina.

His quest for a second term, even if successful, could have pitfalls for Mr. Uribe. To win enough support in Congress, political analysts say, he will have to give opposition politicians important government jobs and support their pet projects. That could weaken his carefully cultivated image as an independent above the fray of Colombia's often crass political machinations.

His effort to retain power would also strengthen the stance of left-leaning Democrats in Washington and opponents in European parliaments who suspect that Mr. Uribe is a closet authoritarian. That could make obtaining aid more difficult.

"It will feed those suspicions that he's an autocrat, and that he's another Fujimori," said Michael Shifter, who tracks Colombia for the Inter-American Dialogue, a Washington-based policy analysis group. "He will not get a lot of sympathy from those quarters."

El Tiempo, the country's leading daily, also warned in a long editorial that a second term for Mr. Uribe could polarize politicians and cause him to expend his energy on that issue, taking him away from more pressing tasks.

But with 64 percent saying they would vote to re-elect him if they could, the overwhelming argument among those who favor the change is that Mr. Uribe, like Franklin Delano Roosevelt, is the man to lead the country if it is to emerge from its darkest hour.

"The biggest reason to do this is to give the government the chance to continue with its programs," Mr. Zuluaga said.

Mr. Uribe's most influential backer is the Bush administration, which sees him as an adept caretaker of Washington's two-pronged effort to curtail drugs and batter the rebels. Since 2000, the United States has provided Colombia with $2.5 billion in mostly military aid.

American officials have hardly hidden their enthusiasm for a second term. When Ambassador William B. Wood gave a speech to a business group earlier this year, he noted that Mr. Uribe had been firm with insurgents.

He added that the United States permits a second term and "that's why we don't see this proposal as antidemocratic."

"This is something that the Colombian people, who must decide about re-election, must take into account," he said. He added that the United States permits a second term and "that's why we don't see this proposal as antidemocratic."

Speaking to Congress on April 14, Sabas Pretelt de la Vega, the interior and justice minister, said Colombia's democracy is mature enough to avoid authoritarianism. Pointing to other countries that permit a second term, he said it would make Colombia more democratic by offering voters a choice.

"A perfect democracy offers all the possible options to citizens," he said, "and one of them is the chance to choose between continuity or change."

But Colombian lawmakers remain divided, with opponents ranging from those who want to run for president themselves to others concerned about the ethical nature of the horse-trading that has surrounded Mr. Uribe's effort to win the right to run again.

In the recent radio call-in show, Sen. Hector Eli Rojas charged that several congressmen had given their backing to the measure in return for juicy diplomatic appointments for relatives.

Calling in, Mr. Uribe shot back, saying the appointments were based on merit. Then, noting that Colombia's most powerful guerrilla chief, Manuel Marulanda, had been waging war since 1964, he asked for long-term support for his programs.

"We have given Don Manuel 40 years, so why don't we give a little more time to Democratic Security," he said. "The country cannot vacillate on public order."