Evangelicals can pick the next US president, according to the president of the Southern Baptist Convention, Ronnie Floyd.

In his latest blog, Floyd asserts the importance of the evangelical vote while attempting to damp down the "God-talk" which has characterised the campaign so far, particularly among Republican would-be nominees.

"The candidates and their public conversations about God range from comfortable to unfamiliar," Floyd says. "Often, this results in confusion within the minds of Christian voters about whom they should support."

He says Christians should be able to evaluate whether someone's faith is genuine. However, in his list of five "major issues", under "Competent Executive" he says: "Evangelical Christians should desire that our president be competent in leading our nation. He or she may not be able to state theological positions and quote Bible verses to your satisfaction, but he or she must be a leader that understands the history of our nation and the Constitution of the United States."

The religious dimension to the Republican nomination race has become controversial, with leading candidates Marco Rubio and Ted Cruz forced to deny they are running to be America's 'pastor-in-chief' and front-runner Donald Trump's spiritual credentials remorselessly scrutinised.

Floyd's other 'major issues' are the sanctity of human life – code for abortion and euthanasia – marriage and family, religious liberty and "appointments, appointments, appointments". The latter is a reference to the row that has already erupted over a successor to conservative Supreme Court Justice Antonin Scalia, whose unexpected death has thrown Republicans into panic at the thought that President Obama's inevitably left-leaning nomination will give the left a majority on the nine-member bench.

Floyd notes that the next president may be able to appoint as many as four new Supreme Court Justices. "We must wake up and ask each candidate: What kind of people are you planning to appoint to any open positions on the Supreme Court of the United States?" he says.

Floyd concludes: "As evangelicals, we need leaders from across the world of business, government, education, church, and beyond to do what is right. Your leadership does matter. The spirit of your leadership is critical. We must be involved in these processes. Leadership matters!

"I say it again. Dear America: Evangelicals Can Pick the Next President, Period. Your leadership matters."