Olivier Douliery / McClatchy Tribune

ST. PAUL, Minn. – Republicans reached out to independent voters Tuesday by featuring Fred Thompson and veteran Democratic Sen. Joseph Lieberman as prime-time convention speakers, while President Bush was to be given a less prominent role, appearing briefly by satellite from the White House.

Bush was to tell viewers that John McCain is best-equipped to handle terrorist threats, according to excerpts of his remarks released in advance.

“We live in a dangerous world,â€Â the president was to say, “and we need a president who understands the lessons of Sept. 11, 2001: that to protect America, we must stay on the offense, stop attacks before they happen and not wait to be hit again. The man we need is John McCain.â€Â

He also was to praise McCain’s support of the Iraq war, saying that “one senator above all had faith in our troops and the importance of their mission -and that was John McCain.â€Â

After a pause Monday to urge support for Hurricane Gustav̢۪s victims, the Republican National Convention became a highly partisan event Tuesday, albeit one with distractions. Foremost was the continuing controversy over presumptive vice presidential nominee Sarah Palin.

McCain, whom the convention plans to formally nominate for president Wednesday night, and the White House continued to defend his choice of Palin. She revealed Monday that her unmarried 17-year-old daughter, Bristol, is five months pregnant, raising questions about how thoroughly the campaign had researched her background before selecting her.

McCain said in Philadelphia that the vetting process was “completely thorough,â€Â and campaign manager Rick Davis had told The Washington Post that the FBI had done a background check on Palin.

However, FBI spokesman Richard Kolko said Tuesday that the FBI didn̢۪t conduct such checks on political candidates.

The White House was firm in backing Palin. “The president of the United States believes that this is a matter that this family has chosen to work through together,â€Â press secretary Dana Perino said.

Bush has his own political problems: His job approval rating has been stuck around 30 percent for more than two years. Though he remains popular in Republican circles, even many delegates have been relieved that he hasn̢۪t been the focus of attention in St. Paul. His scheduled live convention appearance Monday was canceled because of Gustav.

The president was scheduled to appear Tuesday before the major TV networks began live coverage. Perino wouldn’t speculate as to why, saying, “I’m going … to leave the political psychobabble to the press.â€Â

Convention officials changed the schedule early Tuesday to spotlight Thompson, a former Tennessee senator and longtime McCain Senate ally, and Lieberman, the Democrats̢۪ 2000 vice presidential nominee. Both are close to McCain.

They are trying to show voters that the Arizona senator̢۪s appeal is based on his personal qualities and crosses ideological and party lines.

“This election is not about issues,â€Â Davis said in a meeting with Washington Post editors. “This election is about a composite view of what people take away from these candidates.â€Â

Lieberman won re-election to the Senate from Connecticut in 2006 as an independent after losing in the Democratic primary. He̢۪s been close to McCain on environmental, campaign-finance and national security issues, notably the war in Iraq, and has campaigned extensively for him this year.

Dropped from Tuesday̢۪s program was former New York Mayor Rudy Giuliani, who was to deliver the keynote address. He might appear Wednesday, when Palin also is scheduled to speak.

Lieberman, whose speech is titled “The Original Maverick: John McCain,â€Â acknowledged on Fox News that his appearance is “weird, and it’s weird at a very partisan time in our politics.â€Â

“But I think that’s the point of it. I watch year by year people identify more as Democrats and Republicans and we spend more time fighting each other than trying to fight to get something done for the people who were good enough to send us,â€Â Lieberman said.

The Republican Party̢۪s promotion of Lieberman, who still caucuses with Senate Democrats and votes with the party about 85 percent of the time, is aimed at wooing unaffiliated voters, whom McCain attracted in his 2000 and 2008 primary runs and whom he badly needs to win the White House.

Thompson ran for president this year as a conservative alternative to McCain. The two-term former senator from Tennessee, who’s also an actor best known for his role as a district attorney on TV’s “Law & Order,â€Â was an ally of Lieberman during the 1997 Senate hearings on campaign-finance scandals.

Their committee investigated reports that Democrats had used White House facilities to help solicit contributions. Thompson chaired the committee and Lieberman often broke ranks to criticize his own party.

Speeches by friends of McCain recalling his Vietnam War service and other aspects of his personal life were to be featured earlier in the program Tuesday. McCain was held prisoner by the North Vietnamese for five and a half years.

Campaign officials are reworking the Wednesday and Thursday schedules. McCain now is slated to be formally nominated in a roll call of the states, scheduled to begin around 10 p.m. EDT Wednesday.

By David Lightman / McClatchy Tribune