Passage Summary: A pundit thinks we should swap out leaders often because they do their best work early on and get defensive or dishonest if they stay too long.

Conclusion: It is beneficial for national leaders to be removed from office via elections after a short period.

Reasoning: New governments tend to implement reforms early, and if problems persist, long-term leaders are forced to either deny the issues or admit their own failure.

Analysis: The first sentence is the main claim, which the rest of the passage attempts to support. I identified this by noting that the second sentence begins with 'The reason is,' which explicitly marks the subsequent text as evidence. The final sentence provides a psychological explanation for why leaders become less effective over time, further supporting the initial recommendation to vote them out.