I mean what's to prevent me putting up ads that I say aren't political, but are? By the time they've been reported and taken down it's already too late?
Ask all users to report political advertising. If it reaches a certain threshold take down the ad. Manually review it. If it is political then ban the user, payment method and IP address.
If it's hyper-targeted political ads to folks who you can tell via their profiles will absolutely agree with you, what is their incentive to hit that report button?
Not to blow this up too much, but honestly, these aren't ads for shoe polish or a scammy mobile game or some other bullshit. These are ads that make people feel valuable. These are ads that make people feel like their thoughts and opinions, and therefore their entire being is validated.
I've seen many of these ads. Mostly they are scare campaigns.
And in the US it maybe a case that they are targeting their base voters. But in other countries with compulsory voting they are targeting swing voters. And those people absolutely will hit the report button.