Professor Miller went on to say Ryan will be one of about 30 Republicans not seeking re-election.
"Scuttlebutt is that Paul will have to step down from speakership soon", A GOP insider told Axios.
By triggering a House leadership struggle when the party should focus on defending its congressional majorities and advancing Trump's agenda, Ryan dismayed some Republicans already concerned about their prospects with USA voters in November.
U.S. Rep. Ryan Costello, a Chester County Republican (via Twitter): "Speaker Ryan has been a thoughtful and effective leader for our conference and for his constituents in Wisconsin. I like to think I've done my part, my little part in history to set us on a better course".
Banks said it is too early to say whom he, if re-elected, might vote for to take over for Ryan as the top GOP leader in the House.
Ryan served the people of the United States and his constituents in Wisconsin "with distinction and integrity". He wants to spend more time with his children rather than continuing to be a "weekend dad". "He's done a wonderful job, and I'm sure he'll find some other line of work".
House Speaker Paul Ryan delivered a firm endorsement of Majority Leader Kevin McCarthy to succeed him as the House GOP leader next year as a group of conservative Republicans said they're considering a bid to block the choice in order to build their own influence.
Jason Roy after match-winning knock: Wankhede Stadium great place to bat
The onslaught on the spin duo allowed DD to take a safer route against Jasprit Bumrah, Mustafizur Rahman and Krunal Pandya. For Mumbai bowlers, the task is simple: stay disciplined, dry up the runs and force the batsmen to make mistakes.
"None whatsoever actually", Ryan said.
Another name circulating as a possible Ryan replacement was House Majority Whip Steve Scalise of Louisiana, who was wounded by a gunman past year.
Brian Fitzgerald lives in Janesville and said Ryan's justification of spending more time with family is admirable. "But we have a lot of strong Republicans running in contested races", he said.
Meanwhile, President Donald Trump issued his calmest tweet of the morning about Ryan's exit, calling him a "truly good man" who leaves "a legacy of achievement that nobody can question" adding, "We are with you Paul!"
Pew Research calculates that this is the biggest number of departures for the Republican party before an election since a 1930 exodus, which came in the doldrums of the Great Depression and was followed by an era of Democratic dominance.
"We obviously have our differences and we have disagreed publicly and privately, but I do believe I've been doing things that are in the best interests of the country", Ryan answered. "So when I look at that picture I have to say, I don't feel very celebratory, I feel very excluded".
His reasons for leaving could be accepted at face value, while noting that many political experts believes that the actual reason he is leaving is because Democrats are expected to dominate congressional midterm elections in November.