MERIDA, Mexico (AP) – President Bush pledged Wednesday to intensify his push for languishing immigration legislation, standing alongside Mexican President Felipe Calderon who acknowledged he has relatives picking vegetables in the U.S.

Calderon said the family members pay taxes in the United States and “probably handle that which you eat, the lettuce, etc.” But he avoided saying whether they were there legally.

The joint news conference with Calderon was Bush’s last appearance in a weeklong Latin America tour that included stops in Brazil, Uruguay, Colombia and Guatemala. The trip was designed to emphasize U.S. aid for the region and counter criticism that the United States has neglected Latin America.

The president was generally warmly received throughout his travels, and streets were packed with curious onlookers. Still, there were protests at nearly every stop, and Bush was shadowed from afar by Venezuela’s fiery leftist president, Hugo Chavez, who conducted his own tour of Latin America and taunted the president nearly daily.

U.S. immigration laws were a prime topic for Bush. The president said his most important ally in getting Congress to overhaul immigration rules may be a longtime nemesis of Republicans, Sen. Edward M. Kennedy, D-Mass. Once Republicans put aside differences and settle on a course, Bush said, Kennedy may be the one to lead the charge in the now-Democratic Congress because of his vast legislative experience.

“My mood is optimistic because the mood in Congress seems like it’s changed,” Bush said. Bush and Calderon also pledged to step up the fight against illegal drugs.

Calderon has complained U.S. immigration laws are too harsh and has criticized U.S. plans to add up to 700 miles of new fencing along the border. He said he supports efforts by Bush to ease the law. Bush wants to establish a guest-worker program and a path to citizenship for many of the estimated 12 million undocumented immigrants in the United States.

“The borders should bring us together and not separate us,” said Calderon. He said he and Bush discussed the possibility of opening new border crossings and checkpoints and agreed that better jobs in Mexico are the answer – not more border fencing.

“When Mexico grows, the United States benefits,” Bush said.

However, Bush’s problem has always been with conservatives in his own party who want tougher border restrictions and don’t want a guest-worker program. In that sense, the former Texas governor’s long-languishing immigration proposals are closer to those favored by Kennedy and many other Democrats than to those of his own party.

Bush called Kennedy “one of the best legislative senators there is” and noted he had worked with Kennedy in 2001 in winning bipartisan support for the No Child Left Behind education bill, one of the hallmarks of Bush’s first term.

Both Bush and Calderon said they want to make it harder for terrorists and drug traffickers to cross between the two countries – but safer for ordinary travelers.

Bush said that immigration is “an issue that people use to inflame passions” and that “there are strong protectionist sentiments in the United States.”

“I will work, Mr. President, to reject those protectionist sentiments,” Bush said.

He has said he hopes a bill can be approved in the Senate by August, one that reaches a middle-ground. Granting amnesty to all workers now in the country “is not going to fly … nor will kicking people out of the United States work,” Bush said.

As he has throughout the trip, Bush shrugged off a question about Chavez. Asked about Chavez’s influence in Mexico, Bush said his conversations with Calderon “focused on democracy and the rule of law and prosperity.”

For his part, Calderon defended ties with the Venezuelan leader. “We are respectful of the heads of state of other countries, such as Venezuela,” the Mexican president said.

Calderon, 44, a Harvard-educated economist and pro-business conservative, was asked about his own relatives in the United States – and whether they were there legally.

Although he did not answer the second part of the question directly, Calderon said: “Yes, I do have family in the United States, and what I can tell you is that these are people who work and respect that country. They pay their taxes to the government. … These are people who have children, who want these children to be educated with respect for the land where they live and with respect for Mexico.”

Calderon talked about his relatives last month in a speech in Zacatecas, Mexico, which like his home state of Michoacan has been a major source of illegal migrants to the United States.

“Just like you, I have cousins in California, in-laws in New Mexico, uncles in Chicago, who emigrated, who fight and live in the United States,” he said. He said many of them live “a salto de mata,” a Mexican phrase that translates roughly as fleeing or living precariously.

AP-ES-03-14-07 1654EDT