Washington ? Barack Obama on Tuesday abruptly abandoned his nomination fight for Tom Daschle and a second major appointee who failed to pay all their taxes, fearing a lingering ethics dispute would undercut his claims to moral high ground and cripple his presidency in just its second week. “I screwed up,” Obama declared.

“It’s important for this administration to send a message that there aren’t two sets of rules — you know, one for prominent people and one for ordinary folks who have to pay their taxes,” Obama said near the end of a day of jarring developments, little more than 24 hours after he had said he was “absolutely” committed to Daschle’s confirmation.

“I’m frustrated with myself, with our team. … I’m here on television saying I screwed up,” Obama said on NBC’s “Nightly News with Brian Williams.” He repeated virtually the same words in interviews with other TV anchors.

Hours earlier, the White House had announced that Daschle had asked to be removed from consideration as health and human services secretary and that Nancy Killefer had made the same request concerning what was to be her groundbreaking appointment as a chief performance officer to make the entire government run better.

Daschle said in a brief letter to Obama that he refused to “be a distraction” from the new president’s drive for health care reform. Obama said neither he nor Daschle excused the former Senate Democratic leader’s tax errors but that he accepted his friend’s decision “with sadness and regret.”

Unsightly personal tax problems had been piling up for the new administration. Last week, the Senate confirmed Timothy Geithner as treasury secretary, but only after days of controversy over the fact that the man who would oversee the Internal Revenue Service had only belatedly paid $34,000 in income taxes.

Bill Richardson bowed out, too, though his difficulties didn’t involve personal taxes. The New Mexico governor, who was Obama’s first choice for commerce secretary, withdrew amid a grand jury investigation into a state contract awarded to his political donors.

But particularly after the divisive Geithner debate and vote, it apparently became too bitter a pill. Tax issues are easy for the public to understand, and also particularly easy to resent in wealthy officials at a time of widespread economic crisis.

Among those considered for the post before it went to Daschle was Howard Dean, the physician-turned-politician who ran for president in 2004 and recently left as head of the Democratic National Committee. Other possible replacements include Kansas Gov. Kathleen Sebelius, Pennsylvania Gov. Ed Rendell, and Ohio Gov. Ted Strickland.