Here's why Mueller may already have all he needs to lock Trump up

Former federal prosecutor Joyce Vance told MSNBC host Nicolle Wallace that the special counsel might not need to speak to the president because so much exists on Twitter.

Trump was a target in the obstruction of justice probe, according to Wallace, but that Mueller and DOJ investigators have not pushed it because they believed the attorney general would follow the rule of not indicting a sitting president.

"One of the policies the DOJ uses regards a target who is not often subpoenaed to a grand jury," she said. "The reason is if they were subpoenaed, they would simply assert their Fifth Amendment right and decline to answer questions, and the policy says you should not bring someone into the grand jury just to force them to assert their Fifth Amendment right over and over. This could have come into play with the president but we don't know really for certain."

She noted that it's similarly possible that Mueller could have asked for permission to speak with Trump and it could have been denied.

"And it's also a possibility so much of the president's conduct has been in public [and] Mueller felt he didn't need more," she continued. "This is one of those unanswered questions we're left with.

Wallace noted that the president's top lawyers have all said that they refuse to allow Trump to talk to Mueller because he contradicts himself so frequently that he'd commit perjury in the first few seconds.

Trump has said for a long time that he is more than happy to talk to the special counsel and he's not afraid because he's done nothing wrong. When it comes to his lawyers, however, it's the last thing they'll allow him to do. Now, Trump is running away from that, claiming it's more trouble than it's worth.

Wallace also noted that the president is using pardons in a "very obvious" way of obstructing justice. The thread that runs through all of his previous pardons are from those he felt were unjustly accused. Mueller has wanted to know about pardons for over a year, but according to reports, Trump refused to answer any of Mueller's questions on his pardons.

Watch the full exchange below: