WASHINGTON — White House budget director Rob Portman announced his resignation Tuesday, joining a lengthening list of senior officials heading for the exits in the final 1 1/2 years of President Bush's administration.
Bush chose former Iowa Rep. Jim Nussle, one-time chairman of the House Budget Committee, as Portman's successor. Democrats said Nussle's nomination could run into obstacles.
Nussle, 46, ran for Iowa governor in 2006 and lost. He has been serving in Iowa as an adviser in former New York Mayor Rudy Giuliani's campaign for the Republican presidential nomination. Nussle's appointment is subject to Senate confirmation.
"There's no finer man in public service than Rob Portman," Bush said. "Fortunately we've found a good man to succeed him."
"I won't let you down," Nussle promised Bush. "I won't let you down."
Portman, in a telephone interview, made it clear he might seek a return to elective office, either by running for governor of Ohio or for the Senate.
He said he was leaving for personal reasons. His family has remained in Cincinnati and he has been commuting home on weekends for 14 years.
"I need to be home more. I've got three kids ages 12 to 17. It's just been very hard to spend as much time with them and Jane as I need to at this time of my life," he said.
Democrats said Portman would not fare well in politics. "Portman's going to have a hard time ever running again in Ohio after spearheading a Bush economic agenda that caused Ohio to bleed jobs and failed to turn around Ohio's economy," said Chris Redfern, chairman of the Ohio Democratic Party. "Voters will clearly reject that record."
As head of the Office of Management and Budget, Portman ran an agency that touched every major spending decision in the government. He said he was known by some nicknames: "Doctor No. Tightwad. Budget hawk. Penny-pincher, and some not suitable for television audiences."
A six-term congressman from Cincinnati, Portman left Capitol Hill to join the Bush administration two years ago as trade representative and was named budget director a little more than a year ago to replace Joshua Bolten when Bolten became White House chief of staff.
In Congress, Portman was a top liaison between lawmakers and the Bush White House, working behind the scenes from his posts on the Budget Committee and the powerful tax-writing Ways and Means Committee. Despite being a GOP loyalist in a Congress polarized by partisanship, Portman managed to win friends and allies among Democrats.
Sen. Kent Conrad, D-N.D., chairman of the Senate Budget Committee, said he regretted Portman's resignation. "He is a person of credibility and decency that commanded respect on both sides of the aisle," Conrad said. But he withheld praise from Nussle.
"Mr. Nussle has a reputation, deserved or not, of being an intense partisan, quite different from Rob Portman," said Conrad, who said he's already heard concerns about the nomination from about a half-dozen senators. "There are going to be issues with this confirmation."
Since Democrats won control of Congress in November, a number of top administration officials have announced their resignations. Among those leaving or gone are White House counselor Dan Bartlett, chief White House attorney Harriet Miers, political director Sara Taylor, deputy national security adviser J.D. Crouch and Meghan O'Sullivan, another deputy national security adviser who worked on Iraq. Defense Secretary Donald Rumsfeld was forced out immediately after the election as the unpopular war in Iraq dragged on.
Nussle is a former county prosecutor. He was first elected to Congress in 1990, and quickly distinguished himself as a member of the "Gang of Seven," a group of young Republicans who demanded changes in the methods the Democrats used to run the House.
House Republican Leader John Boehner, R-Ohio, praised Nussle's selection. "House Republicans are committed to sustaining any presidential veto over excessive spending by Democrats, and I look forward to working with Jim in that effort this year," Boehner said.
Nussle served three terms as chairman of the House Budget Committee, where he favored budget plans that accommodated Bush's tax cuts as well as the spending restraint that conservative Republicans advocated.
AP Special Correspondent David Espo contributed to this report.
(This version CORRECTS Conrad's home state is North Dakota instead of South Dakota. )