Practically they are selected by caucuses of the majority and minority parties.
Moreover, he ordered that "no officer should be required or permitted to take part in the management of political organizations, caucuses, conventions or election campaigns," and that "no assessment for political purposes on officers or subordinates should be allowed"; and he removed from their offices the heads of the post-office in St Louis and of the customhouse in New York - influential party managers - on the ground that they had misused their official positions for partisan ends.
The act applies to all public elections except that of town officers, and also covers nominations by caucuses and conventions as well.
How would you define caucuses? Add your definition here.