A senior politician in New Zealand has been accused of having an affair.
Most modern commentators say that the private lives of politicians are not relevant to their political life. Personal stuff should be off limits to the news media.
The biblical approach to leadership is different. Elders are expected to be temperate and wise. The best way to discern a potential elder is to look at the way they treat their family and their attitude to money (1 Tim 3:1-7).
Politicians have been given responsibility to make laws for their nation. Laws are enforced morality. Therefore, the moral attitudes of parliamentarians are important. If a politicians will cheat on their spouse, why should theybe trusted to put the needs of their people ahead of their own benefit.