Presidential Line of Succession

[NurseJackie]

30. I found this...

I'll bet there are other more comprehensive and authoritative sources online... but this was just a quickie Google search, and this popped up:

http://www.slate.com/articles/news_and_politics/explainer/2001/03/how_is_a_new_vice_president_chosen.html

Before the 25th Amendment, a vacancy in the office was simply left unfilled. The impetus for the 25th was the assassination of John F. Kennedy--with Lyndon Johnson's ascension to the presidency, there was no vice president in place in case something befell Johnson. Then-Rep. Gerald Ford was appointed under the 25th following the resignation of Vice President Spiro Agnew in 1973. In 1974, after Richard Nixon resigned, Ford became president and selected Nelson Rockefeller as vice president. After a long congressional inquiry, Rockefeller was approved, making them the country's first nonelected president and vice president.

It's incomplete info because it doesn't specifically indicate that Ford needed congressional approval, but we can infer that he likely did have congressional approval because his own choice of Rockefeller needed congressional approval.

This snippet really isn't enough for the foundation of a detailed discussion, but it's enough for me to know what's likely to happen after Trump's impeachment or resignation. I hope it was interesting to you too.