By Kara Rowland

The White House struggled Thursday to explain a second Democratic candidate who said the administration used a potential job to coax him out of a Senate primary, saying President Obama has an interest in avoiding bloody intraparty battles.

Early in the day, the White House confirmed that Deputy Chief of Staff Jim Messina had talked with former Colorado House Speaker Andrew Romanoff about taking a job in the administration. Spokesman Robert Gibbs told reporters later in the day that no laws had been broken.

Less than a week after the White House acknowledged enlisting former President Bill Clinton to intervene in the Pennsylvania Democratic Senate primary, the political ramifications threatened to puncture the president’s claims of changing business as usual in Washington and left Republicans demanding to know whether the White House meddled in other primaries.

“Let’s be clear: There wasn’t a job offered. There wasn’t a job promised. Mr. Romanoff applied for a job in government service during the transition,” Mr. Gibbs said.

Mr. Gibbs tried to distance the president from the failed deal-making attempts, saying he hasn’t talked with Mr. Obama about the Romanoff job discussions.

Republicans called for an independent investigation and said far too many questions remain unanswered about the overtures to Mr. Romanoff and to Rep. Joe Sestak, who defeated White House-supported Sen. Arlen Specter in Pennsylvania.

“Clearly, Joe Sestak and Andrew Romanoff aren’t isolated incidents, and are indicative of a culture that embraces the politics-as-usual mentality that the American people are sick and tired of,” said Rep. Darrell Issa of California, the senior Republican on the House Oversight and Government Reform Committee. “The fact of the matter is, this White House has lost all credibility, and the American people can no longer rely on the word of the White House when it tried to deflect and deny allegations of questionable and potentially illegal conduct.”

In a letter to the White House on Thursday, Mr. Issa asked for a “full and complete list of all elections in which the White House engaged in efforts to persuade specific candidates to drop election bids” by offering a job or something else of value, and details about those offerings.

But Mr. Gibbs, asked by a reporter whether there were any other elections in which the White House discussed job prospects to clear the field, said he was not aware of any.

Mr. Romanoff on Wednesday night made public an e-mail from a White House aide that outlined several positions that would be available to him if he dropped his challenge to Sen. Michael Bennet, who has the support of Mr. Obama. The former Colorado House speaker said he was not promised a job by the White House and made it clear he intended to stay in the race.

In an early-morning e-mail to reporters Thursday, Mr. Gibbs said Mr. Messina “wanted to determine if it was possible to avoid a costly battle between two supporters.”

He said Mr. Romanoff had applied for a position at USAID during the transition and followed up after Mr. Obama took office. Mr. Messina contacted Mr. Romanoff in September, according to the e-mail released by the campaign.

“Romanoff said he was committed to the Senate race and no longer interested in working for the administration, and that ended that discussion,” Mr. Gibbs said. “As Mr. Romanoff has stated, there was no offer of a job.”

Colorado Republican Party Chairman Dick Wadhams said the episode “smacks of the worst kind of Chicago gutter-style politics,” and called on Mr. Bennet and Colorado Gov. Bill Ritter Jr., a Democrat, to “reveal what they knew, when they knew it.” Mr. Ritter appointed Mr. Bennet to the Senate seat after Ken Salazar vacated it to become interior secretary.

“The fact that Romanoff did apply for an administration job in early 2009 doesn’t reduce the culpability of the White House at all,” Mr. Wadhams said. “Romanoff’s own statement connects the job offers and his withdrawal from the Senate race.”

Bennet spokesman Trevor Kincaid said the senator knew nothing of any job offers made to Mr. Romanoff.

“It seems common knowledge that Speaker Romanoff had applied for a few jobs in the administration and several in Colorado. Conversations Michael had with the White House focused on the president’s continued support for his campaign, regardless of what career path Speaker Romanoff chose to follow,” Mr. Kincaid said.

In the least, the Romanoff and Sestak affairs are an embarrassment for a White House that had promised transparency and an end to politics as usual. At worst, Republicans say, the discussions could be criminal.

Mr. Issa said the deal-making sounds like an illegal quid pro quo. Federal law prohibits the offer or solicitation of employment or other benefits in exchange for “political activity or for the support or opposition to any candidate or any political party in connection with any general or special election to any political office.”

The administration has shrugged off remarks by Mr. Issa and other Republicans, who have called for an independent investigation into the Sestak matter. In that case, a memo from the White House counsel said Mr. Clinton, at the behest of Chief of Staff Rahm Emanuel, asked Mr. Sestak whether he was interested in an unpaid advisory board position that would have allowed him to remain in the House and drop out of the Senate race.

But the memo appears to be inaccurate, as the advisory board’s own website says Mr. Sestak would not have been eligible for the position as a sitting House member. Asked about the inconsistency earlier in the week by reporters, Mr. Gibbs said to refer to the memo and that “whatever is in the memo is accurate.”

c Valerie Richardson, reporting from Denver, contributed to this article.