Now that the Senate has voted to clear President Trump of impeachment charges, any judgment of his conduct will be left up to the voters, as fellow Republicans argued it should be.

That is, until Trump leaves office, and loses the immunity from criminal prosecution that presidents are granted by Justice Department policy.

As Trump’s lawyers repeatedly pointed out, the two articles of impeachment approved by the Democratic-controlled House, abuse of power and obstruction of Congress, did not expressly accuse him of crimes. But his alleged dealings with Ukraine’s president — withholding $391 million in military aid, and the promise of a White House meeting to coerce Ukraine into investigating political rival Joe Biden and his son — contain elements of several established federal crimes:

• Extortion: Obtaining money, property or something of value by threat or intimidation.

• Soliciting a bribe: As a public official, corruptly demanding, seeking or agreeing to accept anything of value in exchange for the performance of an official act.

• Foreign campaign assistance: Soliciting, accepting or receiving a contribution or donation of a thing of value from a foreign citizen in connection with an election.

The Government Accountability Office has already found that Trump’s Office of Management and Budget acted illegally by withholding the Ukraine funding because of his own “policy priorities.” That law, passed in 1974 to restrict the president’s authority to block funding approved by Congress, carries no criminal penalties.

But extortion, bribery and seeking foreign campaign aid are all felonies punishable by imprisonment — up to 15 years, for bribery. Under statutes of limitations, each of them can be prosecuted as much as five years after the events took place.

And, unlike an ordinary trial, a president’s vindication from impeachment charges in the Senate does not create a constitutional barrier to future criminal charges for the same conduct.

“It wasn’t a criminal trial,” Stanford law Professor Robert Weisberg said. “There is no double jeopardy.”

The Constitution also specifies that a president who has been impeached, and even one who is later convicted and removed by the Senate, “shall nevertheless be liable and subject to indictment, trial judgment and punishment, according to law.”

Some scholars oppose such prosecutions, including Frank O. Bowman, a University of Missouri law professor and author of the 2019 book “High Crimes and Misdemeanors: A History of Impeachment for the Age of Trump.”

“I could be persuaded otherwise given sufficiently egregious facts, but as a general matter it is a terrible idea for the winners of elections to prosecute the losers” they have unseated, he said. “That way lies a banana republic.”

Harvard law Professor Mark Tushnet agreed, for the most part. “We don’t want follow-on presidents to be able to go after their predecessors (as happens too often elsewhere),” he wrote. But that danger wouldn’t arise, he said, if state prosecutors charged an ex-president with acts of local wrongdoing.

A federal criminal case would almost certainly focus on Trump’s July 25 phone call and other interactions with Ukraine’s president, Volodymyr Zelensky, the centerpiece of the impeachment proceedings.

House managers accused Trump of abusing the powers of his office by withholding vital military funding from Ukraine to pressure Zelensky into investigating Biden and his son, Hunter, who became a board member of the Ukrainian energy company Burisma while his father was vice president.

Trump released the $391 million to Ukraine in September, shortly after an unidentified whistle-blower reported the president’s conduct. While Trump maintains his goal was rooting out corruption in Ukraine, several legal analysts said his actions could fit the definition of extortion, soliciting a bribe, or seeking an unlawful foreign political contribution.

“The evidence of corrupt intent here is vastly stronger than you would see in the vast run of political corruption cases,” said David Sklansky, a Stanford criminal law professor and former federal prosecutor. “I think most federal prosecutors would view it as a very strong case against someone else.”

UC Berkeley Law School Dean Erwin Chemerinsky said, “I think that there is a strong argument that it was the crime of extortion.”

Hadar Aviram, a law professor at UC Hastings in San Francisco, agreed with those assessments, but said Trump’s defenders would question whether the president was acting with a corrupt intent — “Republicans would say ... he’s trying to root out corruption” — and whether investigations of the Bidens were a “thing of value,” a required element in each of the crimes.

The “value” of clandestine political assistance was an issue in Special Counsel Robert Mueller’s investigation of a June 2016 meeting at Trump Tower in New York between campaign officials, including Donald Trump Jr., and a Russian attorney who had promised damaging information on Hillary Clinton. Mueller said he decided not to file charges over the incident because it wasn’t clear how much the information was worth, or whether the participants knew they were breaking the law.

Weisberg, co-director of the Stanford Criminal Justice Center, said he wasn’t sure that the aid Trump was seeking from Ukraine would fit the bribery or extortion laws. “It takes a bit of creative reasoning to say a benefit to Trump’s election, harming Biden, is a thing of value,” he said.

But Sklansky, his Stanford colleague, said courts have ruled that a “thing of value” can be something intangible, like political aid. And in comparison to the information the Russian lawyer allegedly offered about Hillary Clinton, he said, Trump was reportedly seeking a criminal investigation of the Bidens in Ukraine, which would give prosecutors “a stronger argument.”

Some of Trump’s efforts to fend off impeachment could also come in for scrutiny, such as his efforts to raise campaign funds for Republican senators who supported him.

“Any other American who offered cash to the jury would go to prison for felony bribery,” Richard Painter, former chief ethics lawyer for President George W. Bush, said on Twitter.

The president, meanwhile, has already declared that he holds the trump card, so to speak: the constitutional authority “to grant reprieves and pardons for offenses against the United States.”

“As has been stated by numerous legal scholars, I have the absolute right to PARDON myself, but why would I do that when I have done nothing wrong?” Trump tweeted in June 2018, while Mueller was conducting his investigation.

Legal scholars are divided. Tushnet said his “tentative” view is that the president could pardon himself for federal crimes, though not for state charges. But Rick Pildes, a constitutional law professor at New York University, said a self-pardoning power would mean “the criminal law would not apply to the president, ever,” something the Constitution’s drafters could not have intended.

And on Aug. 5, 1974, Mary Lawton, in charge of the Office of Legal Counsel under President Richard Nixon, issued a memorandum saying the president lacked authority to pardon himself, “under the fundamental rule that no one may be a judge in his own case.”

Nixon, facing impeachment, resigned four days later. A month afterward, he was pardoned by his successor, Gerald Ford, for any crimes he may have committed while in office.

Bob Egelko is a San Francisco Chronicle staff writer. Email: begelko@sfchronicle.com Twitter: @BobEgelko