CARTAGENA, Colombia — John McCain hailed the economic benefits of free trade to Colombians yesterday, raising the possibility of an eventual hemispheric-wide agreement even though a weak economy at home has soured many U.S. voters on trade agreements.

Also yesterday, McCain ordered a shake-up of his team, reducing the role of campaign manager Rick Davis and vesting political adviser Steve Schmidt with "full operational control" of his bid for the presidency.

Schmidt becomes the third political operative in the past year to take on the task of attempting to guide McCain to the White House. A veteran of President Bush's political operation, Schmidt will be in charge of finding a more effective message in his race against Demo cratic Sen. Barack Obama, who leads in most public polls.

In Colombia, the GOP presidential nominee-in-waiting also toured the country's largest port by speedboat to review the country's U.S.-backed drug interdiction programs, a day after he praised President Alvaro Uribe for Colombia's anti-drug efforts but pressed him to improve the government's human rights record.

McCain was in the country when Colombia freed Ingrid Betancourt and three U.S. military contractors from leftist guerrillas, but he didn't learn of the rescue until he was aboard a flight to Mexico. Uribe called McCain to inform him of the success.

"He told me some of the details of the rescue, the dramatic details," McCain said. "It's a very high-risk operation. I congratulate President Uribe, the military and the nation of Colombia."

The Arizona senator got in several plugs for a proposed U.S.-Colombian Free Trade Agreement Obama opposes, suggesting the tariffs imposed on American goods now exported to Colombia would disappear under the agreement — creating jobs in the United States instead.

McCain also was promoting NAFTA, the North American Free Trade Agreement, which he has said would benefit the U.S. economy over time. Such agreements have been deeply unpopular in several general election swing states like Ohio and Michigan.

And he said such trade agreements should be broadened to include other countries.

"I would like to see a hemispheric free-trade agreement," McCain said at a news conference here. "I would like to see our continued assistance to countries like Colombia."

Protectionist sentiment at home is worrisome "because history shows that isolationism and protectionism has very unpleasant consequences," McCain said.

But he added: "I am committed to getting every single American displaced from his or her job because of foreign competition ... a new job and a better future."

Obama, who was speaking in Las Vegas to the United Steel Workers annual conference, said trade should work for all Americans and that it was a mistake for the U.S. to open its markets without asking other countries to open theirs.

In remarks aimed at McCain's trade stance, Obama said: "It's not change when he offers four more years of trade agreements that are written by and for corporate lobbyists, agreements that don't protect our workers, don't protect our environment, and ignore the plight of workers abroad. That isn't change."

McCain wrapped up a visit to Colombia and was headed to Mexico on a two-day Latin American swing he insisted was not intended to be political.

The Washington Post contributed to this report.