With the growing evidence of Russian collusion and lying by Donald Trump, Mike Pence, and many others in the administration, the possibility is growing of the first time in American history where the Speaker of the House of Representatives might become President by succession.
It could have happened in 1974 had there not been the 25th Amendment, added to the Constitution in 1967.
That amendment allowed for the appointment of Gerald Ford to replace Spiro Agnew, and within eight months of becoming Vice President, Ford became President.
If this had not been able to happen, there would have been no Vice President for ten months, and Speaker of the House Carl Albert of Oklahoma would have become President, instead of Gerald Ford, when Richard Nixon resigned on August 9, 1974.
Ryan may very well have been aware of Russian collusion in the eyes of some observers, but unless that is proved to be so, he would become President if Mike Pence was forced out, and Donald Trump was forced out, and if there was no time to select a new Vice President under the 25th Amendment.
Ryan, not at all admired, and much criticized by this blogger in 2012, when he was the Vice Presidential nominee for Mitt Romney. would be a terrible successor, with his Ayn Rand libertarian philosophy, and his desire to privatize Medicare and Social Security, and end the concept of government assistance to the needy through Medicaid, Food Stamps, and aid to dependent children.
We are in a time frame where Donald Trump is a nightmare, but Mike Pence, with his overtly theocratic view of religion and government is a different nightmare, and Ryan is a third example of what horrible choices the nation faces from the results of the Presidential Election of 2016.
It will take decades to recover the damage already done, and the damage yet to be done.