WASHINGTON ― Democrats who hope that special counsel Robert Mueller’s investigation into Russian interference in the 2016 election could bring an end to Donald Trump’s presidency may want to consult a constitutional scholar.

Congress could always impeach the president. But short of that, Trump’s job offers him sweeping protections from the types of accountability that normally apply to regular citizens.

Examples abound. Does Trump have massive conflicts of interests? Well, the president is exempt from conflict-of-interest laws. Do officials think Trump’s son-in-law, Jared Kushner, shouldn’t be given permanent security clearance? Well, Trump has the power to grant him clearance anyhow. Does someone want to sue Trump for his actions before he became president? Well, his lawyers say they can’t (a questionable claim). Did Trump violate the law? Well, the sitting president is immune from prosecution.

And ― perhaps most crucially as former FBI director Mueller investigates Donald Trump Jr.’s meeting with a foreign national to discuss dirt on Hillary Clinton ― could someone close to Trump get indicted? Well, Trump can use the power of a presidential pardon to force prosecutors to let it go.

Brian Snyder / Reuters Donald Trump Jr. and President Donald Trump.

So far, there’s been no public indication that Trump is considering preemptively pardoning his son or son-in-law, or others being investigated, including former campaign manager Paul Manafort or former national security adviser Michael Flynn. One of Trump’s attorneys, Jay Sekulow, said Sunday that he hadn’t had any conversations with the president about pardons.

But The Washington Post reported Thursday that Trump has asked aides about how pardons work, though the report characterized the discussions as “purely theoretical.”

Although it’s still an open question whether Trump could pardon himself, should things ever get to that point, the only thing stopping him from preemptively pardoning members of his campaign (or his family) is political backlash. And the only real restraints on the president’s pardon power, says Saikrishna Prakash, a James Monroe distinguished professor at the University of Virginia School of Law, are political repercussions.

“The question of a pardon is always on the table; it’s on the table now,” Prakash said. “I doubt he’s going to issue one now because people will jump to the conclusion that there’s been a crime committed.”

While his position as president may allow Trump to dodge legal accountability, the Russia probe has already had an effect on his political standing. That could ultimately be where the real consequences lie. A preemptive move like pardoning his son would spark massive criticism and cement the belief in many Americans’ mind that whoever received a pardon broke the law. In a similar vein, Trump himself had proclaimed that pleading the Fifth Amendment was an admission of guilt.

“Although you can pardon someone you think is innocent, people will naturally suppose that the person must have done something wrong if the president pardoned them, otherwise they wouldn’t need a pardon,” Prakash said.

Peter M. Shane, a law professor at Ohio State University, isn’t so sure that the normal political rules about pardons apply to Trump. After all, Trump has already admitted that the Russia investigation was on his mind when he decided to fire FBI Director James Comey. The president has repeatedly called the special counsel investigation part of a “witch hunt” and has downplayed his eldest son’s meeting with a Russian lawyer on the promise of damaging information on Democratic presidential rival Clinton, calling it “very standard.”

“In normal times, in times when we did not elect so thoroughly unqualified a president, it would have been political suicide to pardon a family member, or someone involved in an alleged conspiracy with the president himself,” Shane said. “Nixon didn’t pardon any of the co-conspirators in Watergate, and I think he understood to do so only would have hastened what happened anyway.”

But Trump, “seems to believe that that normal laws of politics don’t apply to him,” Shane said. “And he got to be president of the United States, which suggests that some of those rules did not kick in in the usual way.”

Ryan J. Reilly/HuffPost Special counsel Robert Mueller has established an office at the Patrick Henry Building in Washington nearby the federal courthouse.

There are still a few checks on Trump’s power, though, Prakash said.

“It’s the press, it’s impeachment, it’s Congress, and ultimately the populace,” Prakash said. “It’s a lot harder for him to do what he wants if he’s at a 20 percent approval rating, it’s a lot easier if he’s got a 60 percent approval rating.”

On Trump’s business conflicts, there’s not much Trump critics can do other than loudly complain, even though Trump seems “impervious to” and “unmoved” by the criticism, Prakash said. But criticism and public scrutiny, says Shane, would apply more pressure on Republicans to hold Trump accountable.

Republican leaders need to be more afraid of the public reaction to their inaction on the issue rather than they are of losing their supporters for going after Trump, Shane added.

The scrutiny on the Trump administration has already “limited his range of plausible political action,” Shane said. A more radical move ― like Trump trying to get rid of Mueller or pardoning his son or son-in-law ― could further alter political reality. But given the way Trump has tossed aside the typical rules of politics in the past, it’s “not impossible” that the president would preemptively pardon Trump Jr., Shane argued.

“I can only tell you that the first 44 presidents would not have pardoned their children,” Shane said. “I just don’t know about 45.”