Suppose major officeholders from one particular party are not performing well, and this party is not monitoring these officeholders. In what ways could this situation affect the party as a whole?

Question

In the United States, the popularity of the poorly performing officeholders and the president will drop, and that party will probably lose seats, and often the presidency, in the next biennial election.

In a parliamentary system, such as most countries have, the loss of a vote of confidence by the party in power would bring about an even more rapid change of power.