Updated

President Bush is predicting that Hillary Clinton will win the 2008 Democratic presidential primary, according to a new book, 'Evangelical President,' set for release on Monday and written by FOX News contributor Bill Sammon.

Breaking his rule not to talk about presidential politics, Bush told Sammon, who writes for The Washington Examiner, that he thinks the New York senator will defeat Barack Obama in the Democratic presidential primaries, but will fall to the Republican nominee.

“She's got a national presence and this is becoming a national primary,” Bush said. “And therefore the person with the national presence, who has got the ability to raise enough money to sustain an effort in a multiplicity of sites, has got a good chance to be nominated.

"I believe our candidate can beat her but it's going to be a tough race," the president said.

It has been difficult for Bush to remain silent about the 2008 president race, despite his promises not to be the "prognosticator in chief." He has been talking about the race and handicapping candidates during off-the-record chats with visitors to the White House.

After excerpts were released, the White House did not challenge Sammon's account.

"Frankly, it's difficult to not talk about the '08 election a lot," White House press secretary Dana Perino said. "There's a lot of interest in it and it does have consequence."

She denied the notion that Bush was talking up Clinton's prospects in order to energize the Republican base against her candidacy.

"The bottom line is, it really doesn't matter what the president thinks about who will win the Democratic primary," Perino said. "There's going to be a showdown at the OK Corral and they'll figure out whose going to be the nominee and from there the president will campaign vigorously for the Republican candidate.

On the Republican side, Bush has expressed surprise that former New York mayor Rudy Giuliani remains the front-runner despite his liberal positions on social and cultural issues normally critical to the party base, according to The Washington Post. It ran a story about Bush's recent off-the-record chat with television news anchors and Sunday show hosts.

Bush said Giuliani's popularity was a sign of how important the terrorism issue is to Republican voters, the newspaper said. It said Bush cautioned against ruling out Sen. John McCain, R-Ariz., saying he had managed to revive his campaign after an implosion earlier this year.

The Associated Press contributed to this report.