Republican presidential nominee Donald Trump speaks as his Democratic opponent, Hillary Clinton, listens during their presidential town hall debate. (Pool photo by Saul Loeb via Reuters)

Former attorney general Michael Mukasey is no fan of Hillary Clinton or her use of a private email server while she was secretary of state. In a speech at the Republican convention earlier this year, the George W. Bush appointee said Clinton’s conduct in the email case “exquisitely sums up the case against her presidency.”

But even Mukasey said that he would “argue against” Donald Trump’s idea to have a special prosecutor reinvestigate and jail Clinton over her email practices.

“It would be like a banana republic,” Mukasey said in an interview Monday with The Washington Post. “Putting political opponents in jail for offenses committed in a political setting, even if they are criminal offenses — and they very well may be — is something that we don’t do here,” he added later.

Mukasey’s comments come amid growing criticism over Trump’s assertion at the presidential debate Sunday that — if elected — he would tell his attorney general to appoint a special prosecutor to investigate and potentially imprison Clinton.

The Fix's Aaron Blake breaks down Trump's extraordinary call to jail Hillary Clinton over her handling of a personal email server. (Daron Taylor/The Washington Post)

“I didn’t think I’d say this, but I’m going to say it, and I hate to say it. But if I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation, because there has never been so many lies, so much deception,” Trump said. “There has never been anything like it, and we’re going to have a special prosecutor.”

Later, when Clinton said, “It’s just awfully good that someone with the temperament of Donald Trump is not in charge of the law in our country,” Trump replied, “Because you’d be in jail.”

Trump campaign manager Kellyanne Conway said on MSNBC’s “Morning Joe” that Trump’s remark about jailing Clinton was a “quip.” She added, “As for the special prosecutor, I think that’s Donald Trump channeling the frustration he hears from thousands of voters out on the stump every day.”

The prospect of jailing Clinton seems to have traction with many of Trump’s supporters. His remark at the debate Sunday drew cheers from the audience.

The FBI and the Justice Department have closed their investigation into Clinton’s use of a private email server without filing criminal charges. FBI director James B. Comey has asserted repeatedly that “no reasonable prosecutor” would charge Clinton, though she and her staffers were “extremely careless” in handling classified information.

Comey also recently dismissed the notion that he should reopen the matter because of new evidence that had come to light. A spokesman for the Justice Department declined to comment for this story.

Legal analysts say the case being closed in a previous administration would not stop Trump from reopening it, though he might face some hurdles.

Trump would have to convince his attorney general to actually appoint the special prosecutor. That would not seem difficult, given that Trump would appoint the attorney general. But it would politicize the Justice Department in a way that might make many in government uncomfortable.

Former attorney general Eric H. Holder Jr. posted on Twitter, “So @realDonaldTrump will ORDER his AG to take certain actions-When Nixon tried that his AG courageously resigned. Trump is dangerous/unfit.” That refers to Attorney General Elliot L. Richardson and Deputy Attorney General William D. Ruckelshaus, who both left the office rather than obey President Richard Nixon’s order to fire a special prosecutor looking into the Watergate scandal.

Clinton campaign spokesman Brian Fallon wrote on Twitter, “So if Trump wins, he will put his opponent in jail. If he loses the system is rigged. Either way, he is a threat to democracy.”

Critics have said the Justice Department’s investigation of Clinton already was politicized. They have noted that just before Comey announced that he was recommending no charges be filed, former president Bill Clinton, Hillary Clinton’s husband, met with Attorney General Loretta E. Lynch aboard her airplane. Both have said they did not discuss any ongoing cases.

Critics also have said President Obama meddled in the matter in asserting publicly that Clinton did not jeopardize national security because of her email practices. Comey and Obama have said the White House did not pressure investigators in any way.

Mukasey said as a matter of “straight law,” he believed a case against Clinton could be made — though Obama could short circuit that by pardoning Clinton were Trump to be elected. Mukasey said, though, that, “If we were arguing policy here rather than straight law, I would argue against bringing charges.”

“The notion of carrying out prosecutions to pursue a political agenda, that’s something that should never happen,” he said. He declined to say whether Trump’s comments had changed his views on Trump or whether he was supporting the Republican presidential candidate.

Legal analysts said the closest parallel they could think of to what Trump suggested was Holder’s investigation of alleged CIA interrogation abuses, some of which resulted in deaths of prisoners. That controversial probe raised the prospect that intelligence officials might be punished for national security policy in the George W. Bush administration after Bush had left office.

But the Obama White House had warned against becoming mired in past controversies. The investigation ultimately was closed without charges against anyone at the CIA.

One former high-ranking Justice Department official in a Republican administration, speaking on the condition of anonymity so as not to affect future employment, said Trump was “projecting a need to have someone not politically connected to his potential administration look into what he believes are violations of law.”

“What I read between the lines of what Mr. Trump was saying, is, ‘I want the public to be sure that this would be looked at by someone independent of my administration. That seems appropriate to me,” the official said. The official compared Trump’s assertion that Clinton be jailed to Obama’s comment that Clinton did not endanger national security before the case was over.

“I just chalk both of those up to ill-advised political rhetoric,” the official said.

Even if Trump were to get a special prosecutor to examine the case, legal analysts said that is no guarantee Clinton would be charged or convicted. If Comey was correct in asserting no reasonable prosecutor would bring the case, then perhaps a special prosecutor would decline to bring it, or a judge would throw it out early.

“We take pride in the fact that our system works and can reach the right outcome,” said Jacob S. Frenkel, a lawyer at Dickinson Wright who previously worked in the Office of Independent Counsel, “regardless of whether it is politically correct or incorrect.”