A key evangelical leader with influence on American politics emphasized this past week the importance of Republican John McCain’s vice presidential pick on the decision of values voters this fall.

Presumptive presidential candidate McCain’s running mate selection is the “most important” decision of the campaign, said Richard Land of the Southern Baptist Convention’s Ethics and Religious Liberty Commission to CBS News.

If McCain picks a pro-choice running mate, Land said, it will only confirm the mistrust of evangelicals toward the candidate that some have criticized as being too liberal.

“[H]e has no room for error, no margin for doubt,” noted the head of the public policy arm of the nation’s largest Protestant denomination.

Southern Baptists and many evangelicals, Land said, are looking at the VP’s position on the sanctity of human life, the traditional family, and religious freedom the most.

Some vice presidential candidates that religious conservatives would support include Gov. Palin of Alaska, who said she never personally considered an abortion even though her child had Downs Syndrome, and former Arkansas Gov. Mike Huckabee, who during his run this election was highly popular among evangelicals.

Regarding Mitt Romney, Land acknowledged that some evangelicals would have a problem with his Mormon faith. But as for himself, Land said although he does not consider Mormonism a Christian faith, he does not believe that disqualifies someone from being president or vice president.

Another name Land offered was Rep. Eric Cantor (R-Va.), who is the fourth highest person in the House leadership. Cantor is a practicing Jew who has a 100 percent pro-life voting record.

According to a poll conducted by the SBC’s research arm in June, 80 percent of Southern Baptist pastors said they plan to vote for McCain. Only one percent said they plan to vote for Obama, and the rest were undecided.

Land had unfavorable things to say about Obama, who he sees as extreme in his support for abortion.

In particular, the evangelical leader found it troubling that the Illinois senator has opposed a legislation that would require a doctor who performs an abortion on a late term fetus to save the baby’s life if it is born alive.

“And Senator Obama opposed that bill,” Land said. “I don’t know how you can get more pro-abortion than that. And I can’t imagine even John Kerry doing that. And, of course, in addition to which, he voted against the partial-birth abortion ban.”

Land emphasized that he does not make political endorsement and would not say who he would support. However, he said he would vote for candidates that reflect his values and leave people to “connect their own dots.”