Senator Obama of Illinois is seeking to sharpen the contrast with one of his rivals for the Democratic presidential nomination, Senator Clinton, by unveiling an ethics-in-government plan with provisions that appear to target alleged ethics lapses under President Clinton.

Mr. Obama’s “Plan to Restore Trust in Government” calls for mandatory registration of lobbyists seeking presidential pardons and requires disclosure of all donations to presidential libraries. Both are requirements that were widely discussed after the last-minute pardon of a fugitive financier, Marc Rich, as Mr. Clinton left office in 2001.

On the campaign trail yesterday in Manchester, N.H., Mr. Obama gingerly avoided discussion of the Clintons and framed the plan as a retort to the general state of influence peddling in Washington. “Too often the American people don’t know who Washington is working for, and when they find out, they don’t like what they hear,” the Illinois lawmaker said, according to his campaign. “We’ll also expand the definition of lobbying to include people who are lobbying for government contracts and presidential pardons, and we’ll make sure the public knows who those people are and who they’re asking favors from.”

Mrs. Clinton’s campaign did not respond to requests for comment on Mr. Obama’s proposals.

Aides to Mr. Obama indicated that the pardon and lobbying provisions could apply to any president and were not intended as a critique of the Clintons. Mr. Obama’s campaign noted that much of the plan targeted actions taken by President Bush and Vice President Cheney, such as an executive order that allowed former presidents and their representatives to prevent the release of White House records.

Still, political analysts said there was little question that Mr. Obama was raising the specter of ethics flaps that dominated the news in the Clinton era. “Day after day, he’s identifying Hillary Clinton with the establishment and the past,” a professor of politics at the University of Virginia, Larry Sabato, said. “He has to do it subtly. When you scratch the surface, you do find concern about more scandal. There’s a fear there’s more there with Bill. There’s a fear there’s more there with Hillary.” A Democratic talk radio host based in New Hampshire, Arnie Arnesen, said Mr. Obama’s points about pardons and presidential library fund raising were fair. “I think he puts the Clintons between a rock and a hard place,” she said. “There will be people that are offended, but I think any time you bring more transparency into government, especially after this administration, you should be sainted.”

While most Democrats have fond memories of the Clinton administration, Ms. Arnesen said that sentiment does not arise from such issues as the pardon of Mr. Rich. “That was not the behavior we applauded,” she said.

Ms. Arnesen said Mrs. Clinton should not be held responsible for her husband’s conduct with Monica Lewinsky but that other ethics issues were legitimate fodder for the primary campaign. “You can’t embrace your husband’s presidency and say, like Chinese food, you get only A, B, C, and D. If you’re going to embrace him, guess what, honey, you get the worst, too,” the commentator said.

The pardon of Mr. Rich stirred debate because it was advanced outside the usual Justice Department process by a former White House counsel to Mr. Clinton, Jack Quinn, and because Mr. Rich’s ex-wife, Denise Rich, reportedly gave $450,000 to help construct Mr. Clinton’s presidential library.

Mrs. Clinton’s brothers, Hugh and Tony Rodham, also were involved in lobbying for pardons for clients and associates. Congress and federal prosecutors in New York investigated the pardon process, but no criminal charges were brought. An ethics bill awaiting Mr. Bush’s signature requires disclosure of lobbyists’ donations to presidential libraries but not of donations from non-lobbyists.

In 2004, The New York Sun reported that leaders and governments from Saudi Arabia, Dubai, Kuwait, and Qatar were among the donors who gave $1 million or more to the Clinton library. Mr. Clinton’s foundation kept some donations secret and removed a computer display listing many of the donors soon after the Sun reported on it.

Mr. Bush is reportedly seeking to raise about $500 million for his library.