In the two weeks since former president Ronald Reagan was laid to rest, his grieving family has mostly retreated from public view, staying mum as Republican leaders lionize his legacy and promote President Bush as his political heir.

Not the late president's younger son, Ron. Bashing Bush is his new pastime.

With more than 35 million television viewers across the country watching, Ronald Prescott Reagan first hinted at his disdain for the Bush administration this month when he delivered a eulogy during his father's sunset burial service in Southern California.

"Dad was also a deeply, unabashedly religious man," Ron Reagan told mourners. "But he never made the fatal mistake of so many politicians -- wearing his faith on his sleeve to gain political advantage."

Since then, in a series of nationally televised interviews, his comments about Bush have become less oblique and much harsher.

Appearing on CNN's "Larry King Live" Wednesday evening, Reagan denounced Bush's opposition to broadening embryonic stem cell research, calling it "shameful." He called Bush's decision to invade Iraq a "terrible mistake" and said, "We lied our way into the war." Then he said he was eager to see Bush defeated in November.

Two nights earlier, he appeared on MSNBC's "Hardball With Chris Matthews" and scoffed at the new Republican rallying cry that Bush is positively Reaganesque.

"My father never felt the need to wrap himself in anybody's mantle. He never felt the need to pretend to be anybody else," Reagan said. "This is their administration. This is their war. If they can't stand on their own two feet, well, they're no Ronald Reagans, that's for sure."

He returned to CNN again Thursday with another round of denunciations, saying at one point, "My father didn't know George W. Bush from Adam."

It is quite a blitz. And it has Republican leaders across the country amazed and amused, but apparently not alarmed.

Reagan, 46, who is a contributor to MSNBC and an occasional host on the Animal Planet channel, has long been an outspoken political liberal. And some of what he is saying now about Bush is almost tame by comparison with other, more obscure remarks he had made in recent years. In a 2003 interview with the online magazine Salon, for example, he called the Bush presidency "overly aggressive, overly secretive and just plain corrupt." Then he delivered this rhetorical shot: "My father was a man -- that's the difference between him and Bush."

Reagan's agent said Thursday that he was traveling and not available to elaborate on his comments for this story. The White House declined to comment on Reagan's latest remarks. "The president's thoughts and prayers remain with Mrs. Reagan and the entire Reagan family," said Claire Buchan, a Bush spokeswoman.

Ken Khachigian, who was a speechwriter and political adviser in the Reagan White House, said the verbal barbs are not worrying Republicans -- at least not yet.

"If the younger Ron Reagan had a history as a conservative activist, I think this would mean something much more serious," he said. "But he had departed from many of his father's policies long ago, so this comes as less of a surprise."

Besides, Khachigian said, the GOP still has the other Reagan son in its corner: Michael Reagan, the nationally syndicated conservative radio talk show host. Since his father's death, Michael Reagan has said that his father, like Bush, would have opposed stem cell research on moral grounds -- and that the suggestion such research is likely to cure Alzheimer's disease is politically motivated disinformation. "This is junk science at its worst," he wrote in a recent column.

"What Ron Reagan says is going to be offset by what Michael Reagan says," Khachigian said.

Republicans are more apprehensive, he said, about the public stands that former first lady Nancy Reagan, who is not close to Bush, may take in the coming months.

Since her husband's death, she has issued only a statement thanking Americans for showing her family so much affection and support. A Reagan family spokeswoman in Los Angeles declined to comment Thursday on Ron Reagan's remarks over the past two weeks about Bush and his policies.

But last month, speaking at a fundraiser for juvenile diabetes in Beverly Hills shortly before Reagan died, Nancy Reagan said she was "determined to do whatever I can" to campaign for stem cell research because it could help cure a variety of diseases.

"I don't see how we can turn our backs on this," she said, drawing a standing ovation. "We have lost so much time. I just can't bear to lose any more."

In his flurry of appearances this week, Ron Reagan said those remarks were a preview of the active role his mother is likely to take on the issue, even if it means clashing with the Bush administration in an election year.

"If that's what it takes, yes," he told MSNBC. "She's doing what she thinks is right, and she doesn't care who's standing in her way."

In interviews this month, Ron Reagan has talked about Bush in conflicting tones, speaking with contempt for his policies but expressing gratitude for the courtesies the president extended to the Reagan family -- such as the use of Blair House and a presidential jet -- when they came to Washington for memorial services.

Reagan said those gestures "made life a lot easier" and that he also liked the eulogy Bush gave his father at Washington National Cathedral, saying it was "sweet." He also told CNN that he had "no personal animus" toward Bush, even though he believes the president is using religion inappropriately to justify his political actions and does not want him to win reelection.

"There was that answer he gave to the question, 'Did you talk to your father about going into Iraq?' " Reagan said on CNN, noting that Bush replied by saying he had instead spoken to a "higher father, the Almighty."

"When you hear somebody justifying a war by citing the Almighty," Reagan said, "I get a little worried, frankly."

At the burial service for his father, Ron Reagan spoke of politicians who use religion for political gain.On "Larry King Live," Ron Reagan called the Iraq invasion a "terrible mistake" and said he'd like to see President Bush lose in November.Conservative talk show host Michael Reagan has said that, like Bush, his father would have fought stem cell research. Nancy Reagan and Ron have promoted it as a step toward a cure for Alzheimer's.