The following is a list of common political metaphors:

Relating to the executive

• figurehead: a leader whose powers are entirely symbolic, such as a constitutional monarch.
• a puppet government: a government that is manipulated by a foreign power for its own interests
• a lame duck: a politician who has lost an election and is simply waiting for his term limit to expire.

Relating to the legislature

• blank check: legislation which is vaugely worded to the point where it can be widely exploited and abused
• pork barrel legislation or patronage: acts of government that blatantly favor special interest groups.
• a bill rider

Relating to elections

• sacrificial lamb: a candidate who has no chance of winning
• third rail: an issue which is so controversial it is not worth persuing
• stalking horse: a percieved front-runner candidate who unifies his or her opponents, usually within a single political party.
• parachute candidate / carpetbagger: a candidate who runs for election in an area which he or she is not a native resident or has no ties.
• dark horse: a candidate who is largely ignored by opponents yet makes significant gains.
• mudslinging : harsh partisan insults exchanged between candidates
• character assassination: spreading (usually) manufactured stories about a candidate with the intent to destroy his or her reputation in the eyes of the public.
• landslide victory: a huge victory for one side.

Others

• a straw man: an argument which is weak and easily defeated, though usually not the main issue at stake.
• Government in the sunshine: a government which keeps all its records and documents open and easily accesible by the public.
• a witch hunt: a hysterical persuit of political enemies
• a melting pot: a society in which all outsiders assimilate to one social norm.