ABC News broke the story on Thursday that Mike Pence had been subpoenaed by special counsel Jack Smith.

Speaking to MSNBC's Ari Melber, former prosecutor Renato Mariotti said that it's not clear that it's necessarily an escalation in the investigation, but he explained that Pence wouldn't be a target in Donald Trump's document scandal or the Jan. 6 scandal.

"I think what this suggests to me is that Jack Smith is looking at the campaign to pressure Mike Pence to overturn the election in the United States Senate when there is a counting of the electoral votes," explained Mariotti. "I think, you know, that is the one piece of information that only Mike Pence can talk about. He had phone calls with former President Trump where he was allegedly pressured to essentially stop the counting of the electoral votes and send the matter back to the states, and there were repeated conversations with him. And I have to believe that that is why Jack Smith wants to speak with him.

Former acting solicitor general Neal Katyal estimated that it's about a six or seven on a seriousness scale of 1 to 10. He added a margin of error of plus or minus two.

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"We've had presidents who have been subpoenaed before. Thomas Jefferson was subpoenaed very famously in the early 1800s. Richard Nixon was subpoenaed for the tapes and Watergate. Bill Clinton was subpoenaed for his testimony as well. It's not unprecedented to have a law enforcement investigator take this step, but it's a big step," Katyal acknowledged.

He cited the report saying that the DOJ was negotiating with Pence "for months."

"My guess is Pence did what he's been doing for the last two years, talk out of both sides of his mouth," slammed Katyal. "You know, send his aides to say some things but not say much himself and Jack Smith called his bluff and said, you know, we need to get to the bottom of this. Thank heavens for Jack Smith. I thought it was unforgivable that the Jan. 6th committee, which did such a great job, but just let Pence skate and just had testimony from his aides. Pence is kind of like the Forrest Gump in this situation. He's kind of everywhere, yet we've not heard from him. So, I'm glad law enforcement is hearing from him finally."

See the conversation with the lawyers below or at the link here.

Special counsel called Mike Pence's bluff:www.youtube.com