So the argument is going to be by many

"if you can't live up PERFECTLY to the values you advocate you have no business advocating them?"

Isn't it very unreasonable to apply this idea ONLY to family values?

1) Can a politician who never served in the military be allowed to have credible beliefs on military and foreign policy?

2) Can a politician who never set foot on a farm be allowed to have credible beliefs on agriculture policy?

3) Can a politician who received a private school education be allowed to have credible beliefs on public schools.

4) Can a politician who never ran a business of any kind be allowed to have credible beliefs on government economic policies?

5) Can a politician with no legal or judicial background of any kind be allowed to have credible beliefs on the constitution or the role of judgements?

You can go on endlessly. Politicians in general have influence on EVERYTHING at some point but have actual experience in very little.

Finally, one could argue that only a person who has suffered through a terrible divorce or had serious problems with their kids as they grew up can really understand such matters and truly advocate "family values".