As the leader of the newly elected majority in the House of Representatives, Kevin McCarthy was virtually written for the Speaker's role in the House of Representatives - but radicals put sticks in the wheels.
He received 203 votes but would have needed 218 to be elected.
If you cannot agree on a chairman, a new vote is arranged.
This has not happened since 1923 - making Tuesday's vote historic.
Received support from Trump
McCarthy has encountered resistance within his own ranks - some Trump loyalists in the arch-conservative "Freedom Caucus".
They believe that McCarthy is neither conservative nor tough enough to fight the Democrats.
Despite attempts to win them over to his side — even Trump has thrown his support behind it — McCarthy has been unsuccessful.
- This is about something much more important than a person.
It's about whether the Republicans will be able to govern, said Doug Heye, former Republican leader,
A narrow majority is required
Usually, a majority of the House's 435 members, 218 votes, is required to become Speaker.
With only a narrow majority of 222 seats, McCarthy could afford only a handful of enemies.
A speaker can win with fewer than 218 votes — as Pelosi and Republican John Boehner did — if some members are absent, for example.
The Speaker is elected at the beginning of each congressional session every two years.