Christian evangelist and self-styled historian David Barton, center, with hat, at the 2004 Republican National Convention in New York City. (Photo: Joe Raedle/Getty Images)

Last Saturday night in northeastern Iowa, moments before Glenn Beck delivered a 56-minute speech in which he eventually got around to endorsing Sen. Ted Cruz for president, a willowy man with powder puff white hair strolled to the lectern and said a few words.

Not once did the man — who spoke of Beck as "a visionary" and who laid his hands on Beck in prayer beforehand — mention Cruz's name.

David Barton also never told the crowd inside the Five Sullivan Brothers Convention Center his name, even though he introduced other speakers and served as the event's de facto master of ceremonies.

Barton's anonymity was fitting. It was something of a metaphor for the relationship between Cruz and Barton, both of whom hail from Texas. Cruz has maintained a delicate balance in his association with Barton, a figure who is a hero to some evangelical Christians, and a fraud to others.

Few figures represent the split running down the middle of American evangelicalism better than Barton, a 62-year-old self-taught historian (critics call him a pseudo-historian) who has for more than two decades stumped across the country telling conservative Christians that their nation's religious heritage has been covered up and stolen from them by godless secular progressives.

Many in the crowd doubtless knew who Barton was even without an introduction. He is something of a celebrity to those who have viewed his videos at church events or online, or who saw him on Fox News when he regularly appeared on Beck's show. But Barton's reputation has taken some big hits in the last few years, and the integrity of his articles, videos and books has been widely called into question, most aggressively by some conservative evangelical scholars and writers. One history professor at a Christian university said Barton was the conservative version of left-wing academic Howard Zinn.

Republican presidential candidate Ted Cruz is joined on stage by conservative commentator Glenn Beck at Five Sullivan Brothers Convention Center in Waterloo, Iowa, January 23, 2016. (Photo: Aaron P. Bernstein/Reuters)

"Neither of them are historians. They just want to use and manipulate the past to serve their own political or ideological agendas in the present," wrote John Fea, chair of the history department at Messiah College in Mechanicsburg, Pa.

Yet Barton is helpful to Cruz because the presidential candidate has built his strategy for winning the Republican nomination around winning in Iowa, the first state to vote in the primary process, and a place where 60 percent of the GOP electorate identifies as evangelical. Too close an association with Barton, however, would open Cruz up to questions about the influence on his thinking of a man whose views about faith and politics can often sound like Christian reconstructionism — the belief that government laws and policies should be drawn explicitly from the Bible.

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Barton argued in 2011 that the progressive income tax, capital gains tax and the estate tax (or death tax), are all contrary to the Bible. "Jesus has two entire teachings on the capital gains tax," Barton claimed, citing Luke 19:13-26 and Matthew 25:14-29. And, he added, "Jesus did not like the minimum wage."

The Bible does not address any of these issues explicitly. Barton was taking parables told by Jesus in the New Testament and interpreting them quite liberally. Barton said in an interview that his critics often misinterpret or exaggerate his many claims. "I like the Constitution we've got. I'm not trying to replace it with the Bible," he said. When asked about his comments about Jesus' views on tax policy, Barton deflected the question. "What I often say in reporting history doesn't mean that's what I'm advocating for policy right now," he said.

Barton may say statements about Jesus' view of taxes aren't prescriptive, but for Christians who believe the Bible should govern all aspects of their lives, Barton's comments provide a theological justification for ignoring their tax bill that takes higher precedence than the law. If the word of God is explicitly opposed to what the Internal Revenue Service is doing, such a believer might reason with himself, then he or she is in fact bound to oppose and defy the IRS.

These are not the types of statements the Cruz campaign wants their candidate being questioned about on the campaign trail. In September Barton was named as the leader of a pro-Cruz super-PAC, Keep the Promise, making him an official supporter of Cruz's but without any official connection to Cruz's campaign. Of course, if Cruz world was uncomfortable with Barton's endorsement, they wouldn't have wanted him involved with the super-PAC at all.

One of Barton's most noticeable projects so far in the campaign was to gather roughly 300 pastors and "faith