In Houston, former President George H.W. Bush, the father of the current president, stood beside Senator John McCain to offer his endorsement for the Republican presidential nomination. VOA's Greg Flakus reports from Houston.

Senator McCain and the former president came together in a hangar at Houston's Hobby airport and stood side by side with their wives as the 41st president offered his endorsement.

"In the coming election we do not have the luxury of taking a pass on our unique role and responsibilities in the world and the indisputable fact that unites the greatest number of Republicans," Mr. Bush said, "the most independents and many good Democrats as well is that no one is better prepared to lead our nation in these trying times than Senator John McCain."

Senator McCain made note of the fact that he and President Bush had two things in common, both had been naval aviators and both had been shot down. Bush was shot down in the Pacific during World War II and rescued from the water shortly afterwards. McCain was shot down over North Vietnam and was held as a prisoner of war under brutal conditions.

At the meeting in Houston, McCain thanked the former president for his support and spoke of the need to bring the Republican Party together.

"I believe that his endorsement and sign of support honors me and I also think it is very helpful in continuing our effort to unite our party," he said.

McCain faces a deep divide among Republicans. Many conservatives see him as a liberal who has too often compromised with Democrats in order to move legislation through Congress.

One of McCain's biggest problems with conservative Republican voters came two years ago when he co-sponsored an immigration reform bill that they said amounted to an amnesty for 12 million foreigners who had entered the United States illegally. McCain says he now believes the border must be made secure before any other program can be implemented, but he still backs a guest worker program and a path to citizenship for immigrants already here who do not have a criminal record.

Former President Bush addressed conservatives in making his endorsement of McCain, saying that the senator's credentials as a conservative are solid.

"If you have been around the track, you hear these criticisms and I think they are grossly unfair," the former president said. "He has got a record that everyone can analyze in the Senate, a sound, conservative record, and yet he is not above reaching out to the other side."

Senator McCain's only remaining viable opponent in the race for the Republican nomination is former Arkansas governor Mike Huckabee, who is campaigning in the Midwestern state of Wisconsin before its primary Tuesday. Huckabee told reporters there he intends to stay in the race despite the momentum that Senator McCain has developed and the backing he has received from party leaders.