"The strawberries! That's where I had them!"

“Donald Trump was being framed, he fought back. That is not Obstruction.” @JesseBWatters I had the right to end the whole Witch Hunt if I wanted. I could have fired everyone, including Mueller, if I wanted. I chose not to. I had the RIGHT to use Executive Privilege. I didn’t!

— Donald J. Trump (@realDonaldTrump) April 18, 2019

You want a cookie for being such a good boy?  First you might want to read the Mueller report:

"At that point, the president engaged in a second phase of conduct, involving public attacks on the investigation, non-public efforts to control it, and efforts both in public and private to encourage witnesses not to cooperate with the investigation," the report states.
....
The fourth instance stems from Mr. Trump's decision to fire Comey, which directly led to Mueller's appointment. Mr. Trump decided to fire Comey in May 2017 — days after the FBI director declined to tell Congress that Mr. Trump wasn't under investigation.

After Mr. Trump dismissed Comey, the White House insisted he had done so at the recommendation of the Department of Justice. In reality, Mr. Trump had not consulted with the Justice Department before deciding to fire Comey.

In conversations that followed, Mr. Trump indicated the Russia investigation was the real reason he had let Comey go: "The day after firing Comey, the president told Russian officials that he had 'faced great pressure because of Russia,' which had been 'taken off' by Comey's firing. The next day, the president acknowledged in a television interview that he was going to fire Comey regardless of the Department of Justice's recommendation and that when he 'decided to just do it,' he was thinking that 'this thing with Trump and Russia is a made-up story.'"

Because the primary reason you weren't charged and arrested, is that you're a sitting President:

That’s not what Mueller said. He indicated that it would be unfair for him to conclude Trump obstructed justice without charging him in court, which Mueller could not do, because the conclusion would give Trump no opportunity for a rebuttal in a court of law.

— Renato Mariotti (@renato_mariotti) April 18, 2019

He said that he did not "conclude" that the president committed obstruction of justice because "fairness concerns counseled against potentially reaching that judgment when no charges can be brought."

— Renato Mariotti (@renato_mariotti) April 18, 2019

In other words:  yes, you can do it.  But you can't do it with impunity. And if all it does is cost you the election, that'll be enough.