To really understand how a place works, first you have to speak the language.
A strategic procedure carried out by Leadership and their Cloakrooms. There are a few situations in which Senate Leadership might hotline a bill-- the most common is that they want to move it quickly. In that case a member of Leadership asks their Cloakroom to leave an outgoing message for the Senate that the measure will be called up to pass without a vote (by Unanimous Consent). If a single Senator objects to the bill they can phone the Cloakroom clerk, register their objection, and the bill is stopped. Sometimes the Majority leader doesn't really expect a bill to pass by Unanimous Consent but will hotline it anyway-- like a trial balloon to measure a bill's support.
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