“My dad had his conversion before I was even born,” Sam Phillips said Thursday.

“Growing up, my dad went to Jewish camp in the summer,” Mr. Phillips, 26, said of his father, Howard J. Phillips, founder of the Conservative Caucus, who died last month. “We just found this old 8-millimeter video of his bar mitzvah.”

The elder Mr. Phillips helped make Ronald Reagan president and worked with Jerry Falwell in the Moral Majority: he was a titan of conservative Christianity. In 1998, he told an interviewer, using language typical of some members of the religious far right, that true political victory would mean “biblical justice, biblical jurisprudence,” a return to the understanding that the United States “must live by the rules” that God makes.

So I was surprised, as many others were, to learn from his obituaries that Mr. Phillips was born Jewish and did not become a Christian until the 1980s.

Mr. Phillips was exceptional in his fervor, but he was not unique in his journey. The conservative movement, and its Christian wing, includes quite a few Jewish converts to Catholicism and evangelical Protestantism. Besides Mr. Phillips, there are Marvin Olasky, who helped popularize the term “compassionate conservatism”; the columnist Robert D. Novak; Lewis E. Lehrman, who in 1982 challenged Mario M. Cuomo for the governorship of New York; and the activist lawyer Jay Alan Sekulow, founder of the American Center for Law and Justice.

These men are all very different, and in many cases have not met each other. But it is worth inspecting their common experience as converts.

Jewish-born Christians, especially within the Christian conservative movement, offer a window into the expectations and the assumptions of Christians and Jews alike. People who know them may be elated, others uncomfortable — and it can be hard to predict who will feel what. And while converting can make one an oddity in both one’s old and new communities, Jewish heritage can also confer a unique perspective on the conservative Christian world the convert has joined.

Some of these men are not particularly identified with Christianity. Despite his political past, Mr. Lehrman is today known mainly for his philanthropic support of research into American history. But other converts, like Mr. Phillips, move in Christian political circles where Jews are constant objects of interest. Many evangelicals are passionate Zionists, believing the State of Israel heralds Jesus’ eventual return. But their end-times vision often involves the mass conversion of the Jews. So while evangelicals often profess a special love for the Jewish people, that love can feel backhanded to its recipients.

Sam Phillips said that before his father became a Christian, Jerry Falwell would refer to him on television “as his Jewish friend, and how it was important to treat them well” — “them” being the Jews. Both before and after his conversion, the younger Mr. Phillips said, Christians were often enthusiastic about his father’s Jewish ancestry. “I think the only experiences I heard were positive,” Mr. Phillips said.

Mr. Lehrman did not return phone calls, but a pair of 1985 newspaper columns present another angle on conversion: the suspicion it can engender. Mr. Lehrman had been accused of opportunism by Jimmy Breslin, the Daily News columnist: “Lewis Lehrman, the politician, went out and changed his religion from Jewish to Roman Catholic and then announced it in all the political stories.”

William F. Buckley countered that Mr. Lehrman had not advertised his conversion, merely confirmed it when asked by reporters, and that Breslin clearly “intended political harm (Jimmy is an ardent Democrat).”

What’s more, Mr. Buckley added, if Mr. Lehrman were guilty of opportunism, it was a poor attempt at opportunism. The notion, he wrote, “that a conservative Jew can multiply his votes by becoming a Christian is politically superficial.” Mr. Lehrman’s Jewish vote in 1982 was “not large,” and it came mainly from religious Jews who would be affronted, he wrote, “by what they must deem apostasy.” In other words, by converting, Mr. Lehrman stood mainly to lose the votes of Jews upset that he had left.

Converting from Judaism to Christianity may offend fellow Jews, but it can seem heroic to certain ardent Protestants and Catholics, thrilled that a non-Christian has seen the light. Mr. Sekulow, a talk-radio host and a lawyer who often represents Christians in religious-liberty cases, makes his journey from Judaism to Christianity part of his public story. He, too, declined to be interviewed, but one can read his essay “How a Jewish Lawyer from Brooklyn Came to Believe in Jesus” on the Web site of Jews for Jesus.

Mr. Olasky, a former adviser to George W. Bush and the author of “Compassionate Conservatism,” grew up Jewish and became an evangelical after college. He now edits World, an evangelical magazine, and said in an interview that being raised Jewish has its pluses and minuses in the evangelical world.

“I came from a not particularly Bible-oriented household,” Mr. Olasky said, “so there are lots of things, as far as memorizing parts of the Bible, that folks that grew up in the evangelical subculture have, and I just don’t have that.” While he has felt no anti-Semitism from Christians, Mr. Olasky said he has encountered resentment from Jews. One time he was seated at a dinner next to a religious Jew. “And he would not talk with me through the whole dinner,” he said. “I encounter that occasionally.”

As a journalist, however, being from a different background has been an advantage, Mr. Olasky said. He said he had collected around himself at World magazine many reporters, including Christians and adult converts from other faiths, who also did not grow up in the mainstream evangelical subculture. That, he said, gives them an edge.

“We don’t do public relations,” Mr. Olasky said. Indeed, it was World that first reported that Dinesh D’Souza, a conservative Christian, was engaged to another woman while still married to his wife.

“Everyone in the evangelical community is mad at us for some reason at one time or another,” Mr. Olasky added. “We’re not part of the movement.”