A caucus is a group or meeting of supporters or members of a specific political party or movement. The exact definition varies between different countries and political cultures.
Caucus of Democratic voters from Washington State's 46th Legislative District in a school lunchroom, 2008
"Farewell to the Caucus": 1886 cartoon of Francis Schnadhorst, Secretary of the UK National Liberal Federation, leaving Birmingham for London following the split in the party over Irish Home Rule. His luggage includes a scroll marked "Caucus", several string puppets, and a box of "wire pulling machinery", all in allusion to his reputation as a backstage political manager.