WASHINGTON (AP) – House Speaker Dennis Hastert is getting backup from President Bush and other Republican luminaries, while one of the party’s Senate candidates calls for him to resign over the congressional page cybersex scandal.

“He is the head of that institution and this happened on his watch,” said Jill Hazelbaker, spokesperson for New Jersey GOP Senate candidate Tom Kean Jr.

But former Secretary of State James Baker III, an elder statesman of the party, said of Hastert, “He really ought not be a sacrificial lamb.”

President Bush called Hastert last week to reassure him amid allegations that the House speaker did not do enough to protect the teenage House pages from Rep. Mark Foley’s advances.

Senate Majority Leader Bill Frist, R-Tenn., issued a statement supporting Hastert the same day. And Bush’s father, the former President Bush, spoke up for him during an “ABC News” interview.

The boost comes amid wavering support from House Republicans in the wake of revelations that Foley, R-Fla., had been sending inappropriate e-mails to teenage pages for years.

Hastert had blamed Democrats for the election-season revelations, but on Oct. 5 abruptly changed course and took responsibility for the matter.

Hastert vowed not to resign due to his office’s handling of the scandal – “I haven’t done anything wrong,” he said – but it has cost Republicans in public opinion polls.

“I’m deeply sorry this has happened and the bottom line is we’re taking responsibility,” Hastert said at a news conference outside his district office in Batavia, Ill.

That seemed to quiet rumblings about Hastert’s resignation as last week drew to a close and House and Justice Department officials launched separate investigations.

On CBS’ “The Early Show,” Baker said Hastert deserves credit for urging a probe of a sex scandal in the shadow of the midterm elections. And he offered a pragmatic reason for the party to stand by him.

“If they throw Denny Hastert off the sled to slow down the wolves, it won’t be long before you’ll be crying, ‘Hey, you’ve got to throw somebody else over because they knew about it too,’” Baker said.

The bipartisan ethics panel met Oct. 5 for the first time, approving nearly four dozen subpoenas for witnesses and documents regarding improper conduct between lawmakers and current and former pages who may have known about it.

Ethics committee chair Doc Hastings, R-Wash., would not say whether Hastert was among those subpoenaed.

The ethics committee’s senior Democrat, Rep. Howard Berman of California, said the investigation should take “weeks, not months.”

Hastings and Berman will conduct the investigation along with Reps. Stephanie Tubbs Jones, D-Ohio, and Judith Biggert, R-Ill., whose district is next to Hastert’s.

Federal Election Commission records show that Biggert has received $7,000 in campaign cash from Hastert’s campaign committees while Hastings has received $2,500. They vow their relationship to Hastert won’t affect the way they handle the case.