A more thorough explanation:

Definition: A joker is a clause or amendment added to a legislative bill that makes it unclear or ineffective without causing opposition during its passage. It is also known as a rider or extraneous amendment that is not related to the main subject of the bill.

• A bill about education funding includes a joker clause that states the funds can only be used for schools in certain districts, but does not specify which districts. This makes the bill unclear and ineffective.
• A bill about environmental protection includes a joker amendment that allows oil companies to drill in protected areas. This amendment is not related to the main subject of the bill and can cause confusion and opposition.

These examples illustrate how a joker can be used to manipulate the passage of a bill by making it unclear or ineffective. It can also be used to sneak in unrelated amendments that may not have passed on their own. This can be harmful to the legislative process and the public interest.