"It is a reflection," Lieberman said, "of Christian Americans saying to me in those magical words God bless you 'We know you are a religious person, you don't have the same religious faith and observance we do, but we're glad you're running.' "
He anticipates Romney will strike a chord with Americans, who, although they may not agree with Mormon doctrines, will respect the basic values he and his Utah-based church represent.
Lieberman, speaking to more than 5,000 students at BYU's Marriott Center, said the issue of Romney's religion dubbed a "cult" by Baptist Pastor and Texas Gov. Rick Perry backer Robert Jeffress goes back to the early days of the republic.
Lieberman, an independent senator who caucuses with the Democrats, said the nation's founders took care to enshrine religious liberty in the Constitution, both in the First Amendment's ban on government establishing or interfering with churches and the Article 6 prohibition against religious tests for public office.
The Founding Fathers, Lieberman said, proclaimed a belief in God in the Declaration of Independence but they believed people deserved the freedom to worship or not worship as they saw fit.
Lieberman, who said he had respect for Mormons and noted that Latter-day Saints and Jews share similar beliefs and practices, called respect for religious beliefs a part of American values.
That's not to say that there have been barriers. In the 1960s, John F. Kennedy's campaign was viewed with suspicion because of his Catholicism in much the same way Romney and former Utah Gov. Jon Huntsman are viewed for their Mormonism by many evangelical Christians.
"President Kennedy said if the [1960 presidential] election is decided on the basis that 40 million people who were Catholic lost their chance to be president the day they were baptized, ultimately the nation is the loser," Lieberman said. "The same will be said of Governor Romney and Governor Huntsman."
If Romney secures the Republican presidential nomination, Lieberman said, that would not only open another door, but also give Americans a chance to learn more about Mormons, just as his vice presidential run put a spotlight on Judaism.
In the end, Lieberman said, voters will look at what the candidate brings to the table, with faith not being part of the equation.
He noted that the Gore-Lieberman campaign actually had a half-million more votes than George W. Bush and Dick Cheney, a contest the Republicans ultimately won after the U.S. Supreme Court halted a recount of votes in Florida.
"[The Gore-Lieberman] ticket was judged on its quality," Lieberman said, "rather than on my religion."
BYU President Cecil Samuelson commended Lieberman for urging people to be true to their principles. Samuelson is also quoted in Lieberman's book The Gift of Rest on the virtues of observing the Sabbath.
Also attending Tuesday's forum were LDS Church apostles L. Tom Perry and Quentin L. Cook.