After his Iran-contra investigation, Lawrence E. Walsh issued a report with definitive conclusions about Presidents Ronald Reagan and George Bush even though he accused neither of a crime. Ken Starr, operating with different authority than Mr. Mueller under a since-expired law, sent the House a list of 11 impeachable offenses he believed Mr. Clinton had committed.
“Mueller is murkier than each of those,” said John Q. Barrett, an associate independent counsel under Mr. Walsh and now a professor at St. John’s University School of Law. Mr. Mueller, he added, is more rooted in the Justice Department than any of his prominent predecessors and operating under rules that limited his autonomy, unlike Mr. Starr and Mr. Walsh.
“There is a kind of G-man temperament that Mueller has, maybe more than anyone we’ve seen in our lifetimes,” Mr. Barrett said. “On the other hand, one doesn’t have to read his report very carefully to see that there is a whole bunch of alarming material there.”
Mr. Mueller made clear that Mr. Trump’s accusers will have to read that report without his help, if he has anything to say about it. He has no desire to play star witness at a congressional hearing, and, if forced to testify, he said he would offer nothing more than what he has already produced in 448 pages.
Without a more cooperative investigator to produce a televised dramatization of the case against Mr. Trump, as Mr. Starr did against Mr. Clinton, Democrats will have to weigh whether they can change the minds of the public. A recent Reuters/Ipsos poll showed that support for impeachment has risen in recent weeks to 45 percent, but still below a majority.
Republicans said they felt confident Democrats would make themselves look like partisan Trump haters who refuse to give up.
“The Russia interference story has long outlived its shelf life, but Democrats in Congress seem intent to pursue it no matter the lack of evidence,” said Sara Fagen, a Republican consultant who served as White House political director under President George W. Bush.