WASHINGTON (AP) — John Boehner, prone to shedding sentimental tears, will probably need his hankie Thursday. But you might catch him grinning, too, as he relinquishes the speaker's gavel and the burden of trying to herd defiant House Republicans.
The ceremony of selecting a new speaker of the House, the person second in line for the presidency, rarely takes on the drama created by Boehner's surprise resignation and the chaotic search for a replacement. Republicans on Wednesday nominated his reluctant successor, Rep. Paul Ryan of Wisconsin.
Here's a primer on the handover of power Thursday morning:
HOW IT'S DONE
The Constitution says the House shall choose a speaker. The votes are normally held every two years in January, when a new Congress convenes after a November election.
Mid-session votes like Thursday's are rare, sometimes following the death of a speaker in office. The last special election was in 1989, when powerful Texas Democrat Jim Wright resigned the speakership amid allegations that he broke ethics rules limiting gifts to lawmakers.
Speakers are elected by a roll call vote of the full House.
Each political party meets first to select its own nominee, and lawmakers rarely cast votes for a member from the other side, so the majority party controls the speakership.
Still, lawmakers can vote for anyone they want. They sometimes protest their party's choice by calling out another name or just saying "present."
When Boehner was elected to his third term as speaker last January, 25 Republicans voted against him — the largest such revolt within a party in more than 100 years. It was a public display of the bitter divisions within the GOP that eventually drove him out.
Under congressional rules, the new speaker must be elected by a majority of the members who actually cast votes.
If all 435 House members vote, Ryan needs 218 votes to win.
When no candidate gets a majority, the House keeps voting until enough lawmakers switch their votes to reach a majority for someone. That hasn't happened since 1923, when it took nine ballots to elect a speaker, according to the Congressional Research Service.
The longest speaker election, an 1856 vote roiled by disputes over slavery and immigration, took two months and 133 ballots to pick a winner.
The process of choosing Ryan was especially messy, with a group of hard-line conservatives threatening to block anyone not to their liking and Boehner's chosen successor, Majority Leader Kevin McCarthy, forced to abandon his bid for the job.
On Wednesday, by secret ballot, House Republicans settled on Ryan as their best hope for placating a few dozen conservative firebrands without alienating the bulk of more-establishment members. He got 200 votes from the House's 247 Republicans, with more expected to rally to his side in the public roll call Thursday.
According to tradition, most if not all of the chamber's 188 Democrats will vote for their leader, Nancy Pelosi of California, even though she has no chance of winning back the post she held before the Democrats lost majority power in 2010.
ABOUT THE PRESIDENCY
The Constitution leaves it up to Congress to decide who should take over if some set of circumstances leaves both the president and vice president unable to lead the nation. Congress put the speaker of the House next in line, through the Presidential Succession Act of 1947.
No speaker has ever been called to the White House. Some have found themselves one heartbeat away, during periods when there was no vice president.
Ryan, who was the Republican vice presidential nominee in 2012, is widely presumed to be interested in a White House bid.
Taking on the impossible-seeming task of uniting fractious Republicans looks like a risky move politically. But it will get his name in front of the public, and that could help his future ambitions.
History doesn't offer much encouragement: Only one speaker has gone on to the presidency — James K. Polk, elected in 1844, and he served as Tennessee governor in between the two roles.
Henry Clay, a renowned speaker of the early 19th century, said the job was "to remain cool and unshaken amidst all the storms of debate" and protect the law and rules of the House "from being sacrificed to temporary passions, prejudices, or interests."
Some speakers have grabbed vast powers for themselves; others shared authority more freely with committee chairmen and other lawmakers.
A key source of power is the speaker's ability to control which bills come to the floor for a vote.
The speaker also appoints the chairmen of some key committees and holds substantial sway on other chairmanships.
They do lots of fundraising for their members' re-election campaigns, which also helps them inspire loyalty.
In addition to that, and ceremonial duties such as presiding over joint sessions with the Senate, they also have to keep representing the folks back home in their districts.
Boehner will call the House into session for the final time Thursday morning and deliver his farewell speech.
Each party will nominate its choice, and lawmakers will announce their votes one by one.
Boehner will announce the winner — presumably Ryan — and Pelosi will present him to the House as the new speaker.
Ryan gives a speech, and then is sworn in by the longest-serving member, Democrat John Conyers of Michigan, first elected in 1964.