The only way politics will turn on religion is if a totalitarian regime takes power. This would have to have zero tolerance for any religion of any kind--and you better believe that the witlesses will be among the first to be hit. This could create quite a crisis, and our freedom would be suspended. Chances are, such a totalitarian society would only last about 25 years, because people without religion are going to think better than those with religion.
However, this will not happen on a worldwide basis. You could have a totalitarian. zero-tolerance-for-religion government in the United States, but what is that going to do about the Muslim countries or places like Australia? Or, you could ban religion in Brazil and China, but what good would that do if you happen to live in England where religion is still going strong? And, how is the UN going to ban religion? They could issue trade sanctions against any country that doesn't ban religion, but there is going to be someone that is going to break that rule or a non-member that is going to still allow religions. Religion is not going down by political force.
The only way to bring religion down is to get people in them to start thinking for themselves. Once a Christian realizes that the Bible lies and that Jesus didn't want people following him, there is a good chance that there will be one less Christian. If a Muslim sees that the Quran lies, that means one less Muslim. If everyone in the world sees that, there goes religion. And, if very few people still believe in religion, it will not have enough money to sustain itself, and the church will still go belly up. All the while, the laws can still permit religion--and even give them tax breaks. If people don't contribute, the churches go belly up.