La Plume, Pa. ? President Bush campaigned Thursday for a congressman who has confessed to adultery and a senator accused of racial insensitivity, seeking to boost incumbent Republicans once safe for re-election but now in peril.

Bush’s appearances for Rep. Don Sherwood here and for Sen. George Allen in Richmond, Va., found the White House on the defensive for the decision to try to help candidates in such straits as the GOP struggles to keep control of Congress.

“I think the president understands that it’s important to set high standards,” said spokesman Tony Snow.

Bush, whose low approval ratings and identification with the unpopular war in Iraq have caused some Republicans to see him as a liability, tried to keep the focus on his contentions that Democrats would go soft on the war on terror and raise taxes if handed a majority in the November elections.

But the pictures of the day were of Bush descending from Air Force One in Pennsylvania alongside Sherwood, his wife and one of their daughters, who were secreted onto the plane to set up the photo-op, and of the grinning foursome’s appearance later at a local farmer’s ice cream store.

Allen opted for a slightly less robust presidential embrace, merely greeting Bush at the bottom of his airplane’s stairs and keeping a bit of a distance on their pumpkin-buying stop at a roadside stand. Sticking closely by Allen’s side throughout was state Sen. Benjamin Lambert, who is black and a Democrat who has endorsed the GOP senator.

President Bush makes an unscheduled campaign stop Thursday at Manning's Ice Cream with Rep. Don Sherwood, R-Pa., second from left, Sherwood's wife Carol, second from right, and their daughter, Maria, in Clark's Summit, Pa.

Sherwood has held one of the safest seats in Congress, his conservatism playing well in his heavily Republican, rural district in northeastern Pennsylvania. Democrats didn’t even bother fielding a candidate in the past two elections. But last year, Sherwood admitted to a five-year extramarital affair with a woman 35 years his junior. He settled a lawsuit that claimed he had choked her – he has denied he abused her – and has aired a campaign commercial asking constituents to forgive his infidelity.

Helping to raise more than $300,000 for Sherwood, Bush only obliquely addressed the controversy.

The president’s main message at the event was that the Iraq war is part of the broader anti-terrorism effort.

He warned ominously that Democratic control of Congress would result in a chairman of the House tax-writing committee who would cut off funding for troops in Iraq and a House speaker, referring to now-Minority Leader Nancy Pelosi, who voted against a string of bills: renewing the Patriot Act, creating a Homeland Security Department, waging the Iraq war and authorizing a warrantless wiretapping program.

Later, scooping about $500,000 into Allen’s campaign account, Bush switched his emphasis to the other pillar of his campaign-trail speeches: that Democrats would preside over an economically damaging increase in taxes on American families and businesses.