If number 1: If Trump is definitively found to have colluded directly with Russia, he would be forced to resign or be impeached.
If number 2: If Trump is removed, Vice President Mike Pence would become president.
If number 3: If Pence becomes president, he should resign too, given that he benefited from the same help from Mother Russia.
If number 4: If Pence resigns before appointing a vice president, Ryan would become president.
If number 5: If Ryan becomes president, he should do the right thing and choose Clinton for vice president. Then he should resign.
I've been told an acting President, as Ryan would be until the Supreme Court handed the job to Tillerson after ruling that even if the US House Speaker is an "officer" of the United States, a former Speaker (he'd have to resign to become acting President) certainly isn't, cannot nominate a VP.
Is Lessig a Professor of Growing Magic Mushrooms?
Imma guess he freebases his own dried turds.