Twenty-second Amendment to the United States Constitution
Some argue that the 22nd Amendment and 12th Amendment bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the presidential line of succession. Others contend that the original intent of the 12th Amendment concerns qualification for "service" (age, residence, and citizenship), while the 22nd Amendment, concerns qualifications for "election", and thus (strictly applying the text) a former two-term president is still eligible to "serve" as vice president (neither amendment restricts the number of times an individual can be elected to the vice presidency), and then succeed to the presidency to serve out the balance of the term (though prohibited from running for election to an additional term).
Michael Avenatti
Avenatti has on several occasions, including in a post to Twitter, expressed interest in running for President of the United States in 2020. In a CBC TV interview published in September 2018, Avenatti said he would run in 2020 only against Trump or Pence. In an October 2018 interview with CNN, Avenatti said:I have not announced whether I'm running; I haven't made a decision. What I will say is, I'm travelling around the country; I'm very encouraged by people and their reaction to me, and a lot of people are encouraging me to run, because they think that we need a fighter; we need someone to call this president out on his conduct, and we've gotta get back to making this nation what it once was.