When Senator John McCain won the endorsement of the Rev. John C. Hagee in February, his campaign hoped it would shore up his conservative credentials among evangelicals and build enthusiasm among a voting bloc that would be critical for him in November.

But since then, Mr. Hagee has been on the defensive over some of his views about Catholics and Jews, and he and Mr. McCain’s campaign have been silent about his endorsement.

The controversial endorsement points to Mr. McCain’s tenuous relationship with conservative evangelicals, a group that President Bush courted with tremendous success and that Republicans have come to view as vital to their prospects in many states.

The McCain campaign sought Mr. Hagee’s support, Mr. Hagee said in a recent interview. But after the two announced the endorsement at an event on Feb. 27 in San Antonio, Mr. Hagee’s hometown, the campaign has stopped talking about it.

A spokeswoman answers questions by referring to a statement Mr. McCain made the day after the endorsement, when it was greeted with a barrage of criticism: “In no way did I intend for his endorsement to suggest that I in turn agree with all of Pastor Hagee’s views, which I obviously do not.”

Mr. Hagee also declines to discuss the endorsement, and in interviews and during a conference call with reporters on Monday, he would not even say how it had come about. “For the present time for many reasons,” Mr. Hagee said in an interview late last month, “it is better that I don’t comment on the campaign in any way.”

The controversy surrounding Mr. Hagee seemed to take the McCain campaign by surprise, said David C. Leege, an expert on Catholic voters and an emeritus professor of political science at Notre Dame.

Mr. McCain began seeking Mr. Hagee’s endorsement more than a year ago, trying to bolster the campaign’s support among evangelical voters. Republican leaders are concerned that evangelicals will sit out the election in November, depriving Mr. McCain of votes that may be crucial to beating the Democratic nominee.

Mr. Hagee has a large following and a vast reach on radio and television. But he has also been criticized by Catholics for comments about the church and, recently, by some Jews for his views on Israel.

After Mr. Hagee endorsed Mr. McCain, the criticism was fierce and Mr. McCain soon distanced himself, issuing a series of statements until he announced he was “repudiating” those of Mr. Hagee’s views that might be considered anti-Catholic.

A McCain adviser acknowledged on Monday that the campaign had failed to look into Mr. Hagee’s background adequately and said that as a result the campaign’s procedures for vetting endorsers had improved.

Mr. McCain, who does not talk about religion publicly, has a rocky history with conservative Christians. Eight years ago, he called the Rev. Jerry Falwell and the Rev. Pat Robertson “agents of intolerance.”

But as he prepared to run for president again, Mr. McCain was the graduation speaker at Mr. Falwell’s Liberty University in 2006, met with Mr. Hagee in Texas and spoke at his Night for Israel in Washington in 2007.

As recently as last week, however, James C. Dobson of Focus on the Family criticized Mr. McCain in an opinion article in The Wall Street Journal for his unwillingness to support a federal amendment against same-sex marriage and to oppose federal financing for stem cell research.

Mr. Hagee, 68, is not as well known as Dr. Dobson or Mr. Falwell, but he is powerful within the “strongly conservative political wing of the evangelical community,” said D. Michael Lindsay, an expert on evangelical political involvement and assistant director of the Center on Race, Religion and Urban Life at Rice University. The author of many books, Mr. Hagee also talks twice daily on 75 radio and 125 television stations and has a personal e-mail list of two million supporters, Mr. Lindsay said. “It is his constituents who are least likely to support McCain,” he said.

Immediately after the endorsement, though, the Catholic League condemned him as being anti-Catholic. The group accused him of branding the Roman Catholic Church as anti-Semitic and of referring to it in his apocalyptic theology as “the great whore of Babylon,” the symbol of a false church.

Mr. Hagee said that his views had been misrepresented and that he had never been anti-Catholic. He said that he had examined anti-Semitism across Christian denominations and that the reference to a false church applies to those Christians who do not believe in the Gospel.

Mr. Hagee was also denounced last week by Rabbi Eric Yoffie, the president of the Union for Reform Judaism, the country’s largest branch of Judaism. Rabbi Yoffie called Mr. Hagee and his group, Christians United for Israel, “extremists.”

Mr. Hagee, who is traveling in Israel with 1,000 evangelicals, defended himself in a conference call on Monday, saying that Rabbi Yoffie “relies on a few quotes from me and others pulled out of context. Rabbi Yoffie ignores our record because this record completely undermines his claim.”

Mr. Hagee’s prominence is partly explained by his activism on behalf of Israel. His group has a mailing list of 80,000 “spiritual leaders,” Mr. Hagee said, and he has given about $30 million to Israeli causes in the last five years.

The group’s view, which it has expressed to members of the Bush administration, is that Israel should not be pressured “into making territorial concessions that she does not want to make,” Mr. Hagee said Monday. He does not support a two-state solution to the Israeli-Palestinian conflict.

While many Jewish leaders welcome Mr. Hagee’s support, Rabbi Yoffie, at a meeting in Cincinnati of the rabbinate of Reform Judaism, asked leaders to reject Christians United for Israel. “If implemented,” Rabbi Yoffie said, “these views would mean disaster for Israel, and would lead to diplomatic isolation, increased violence and the loss of Israel’s Jewish majority.”

Most of the 55 million evangelical adults in the United States believe in the literal second coming of Christ, but Mr. Hagee is one of approximately nine million who are pre-millennial dispensationalists, said John Green of the Pew Forum on Religion and Public Life. By putting together passages from biblical books like Revelation, Daniel, Ezekiel and others, they amass “a puzzle to produce an amazingly detailed scenario of the end of history,” said Timothy Weber, author of “On the Road to Armageddon: How Evangelicals Became Israel’s Best Friend.”

For the prophecies to be fulfilled, proponents believe, Jews must control Israel.

Mr. Hagee has said he supports Israel because of biblical mandates to “bless” the Jews. “Our support of Israel has absolutely nothing to do with any kind of End Times scenario,” Mr. Hagee said. “All the Old Testament prophets prophesied that the state of Israel would be reborn.”

Mr. Hagee, meanwhile, has been trying to patch up relations with Catholic leaders. He met recently in New York with Deal W. Hudson, a former Bush campaign strategist, who said he was asked “to choose other Catholic leaders” for Mr. Hagee to meet with.

But Mr. Hagee’s choice of Mr. Hudson as Catholic liaison may create its own problems: Mr. Hudson had to resign in 2004 as head of Catholic outreach at the Republican National Committee after old accusations of sexual misconduct surfaced.

Copyright 2008 The New York Times Company