John McCain's trip here Tuesday was part of an unusual three-day presidential campaign swing to Latin America with a dual message for voters back home.

By visiting Colombia and Mexico, McCain wants to emphasize to all voters that he has stronger foreign policy credentials than Barack Obama, his Democratic rival.

McCain also wants to appeal specifically to Hispanics in the United States by expressing his concern for problems in Latin America.

''Hispanics are a very important voter bloc in some key states,'' Republican pollster Neil Newhouse said, citing Nevada, New Mexico, Colorado and Florida. ''It's a bloc that Obama didn't score well with against Hillary Clinton'' during the Democratic primaries.

President Bush got 44 percent of the Hispanic vote in the 2004 election, according to exit polls. McCain would receive 28 percent of the Hispanic vote in Newhouse's latest poll for NBC News and The Wall Street Journal.

''The visit by Senator McCain demonstrates that we exist and are important for the United States,'' said Ricardo Tribin, president of the Colombian-American Chamber of Commerce in Miami. ``It's a magnificent gesture.''

While in Colombia, McCain will highlight his strong support for a free-trade agreement that's stalled in Congress because of Democratic Party opposition.

Like most Democrats, Obama opposes the deal because of job losses in the United States linked to international trade and because of violence against union leaders in Colombia, where they're being killed at alarming rates.

WEB MESSAGE

McCain began broadcasting a Web advertisement Tuesday in which he says, "We must encourage more trade agreements to create more jobs on both sides of the border; that's why I'm behind the Colombian Free Trade Agreement.''

In Cartagena, the Arizona senator also is expected to express his strong support for Colombian President Alvaro Uribe, the United States' closest ally in South America.

The United States is spending about $600 million a year for Plan Colombia, which since 2000 has helped the government combat cocaine trafficking and a longtime leftist insurgency.

Colombia is the world's biggest source of raw coca leaf, the basis for cocaine.

The government has been fighting the Revolutionary Armed Forces of Colombia, better known as the FARC, for 44 years. The FARC finances its operations through cocaine trafficking.

The conservative Uribe was elected in 2002 in part on a promise to crack down on the FARC, and he has delivered. The group has lost three of its top seven commanders this year and is losing fighters every day to death, capture or surrender.

Many international groups want McCain to use his bully pulpit to express support for rooting out paramilitary influence in Colombia's Congress. Uribe is tied to many of those lawmakers.

''We would like McCain to come out strongly for independence of the judiciary and for thoroughly investigating the paramilitary groups and holding accountable their accomplices,'' said Maria McFarland, who follows Colombia for Human Rights Watch. ``Twenty percent of the Congress is under investigation for its links to paramilitary groups that are responsible for widespread atrocities.''

It's no surprise that McCain staffers chose Colombia as the first country their candidate would visit in Latin America.

Nowhere else in the region do Latin Americans have such high regard for the United States and Bush as in Colombia, said Marta Lagos, who oversees the Latin Barometer poll.

''Unlike other parts of Latin America, they don't feel like they've been forgotten by the Bush administration, thanks to the support for Plan Colombia,'' Lagos said in an interview from Santiago, Chile.

Cartagena, on the Caribbean coast, is probably Colombia's safest big city. Local officials like to note that Bill Gates and former President Clinton have visited in recent years.

TOURIST-DEPENDENT

Cartagena is Colombia's version of New Orleans, a tourist-dependent city with a colonial area built by the Spanish known as the ''historic downtown.'' It's a Caribbean version of the French Quarter.

Locals seemed to welcome McCain's high-profile visit.

''The United States and Colombia, we are friends,'' taxi driver Tadeo Sierra said Tuesday, flashing a thumbs up.