There is nothing weird about it. It's the good old double standard. Clinton wasn't just a philanderer, he was a world class sexual pervert enabled by his wife who is now the secretary of state.
And Clinton had a string of women going all the way back to Paula Jones, when he was governor and then a long relationship with Gennifer Flowers and others and all before he was president, I think. The public knew of these women and so did Hillary, and Bill Clinton still became president, and continued with his follies until he was impeached.
I don't feel that any of his infideliities made him a lesser president. In fact, I think they helped. He was a good looking man with power and lust for young beautiful women, and it all worked well for him, until it didn't.
Newt is a changed man and I don't believe he would ever be a serial womanizer. He has been married since 2000 to Calista, and had a relationship with her for 6 years prior. It will be interesting to see how it all plays out. But Newt knew this would come up, before he tossed his hat in the ring, and I am sure he will be a better man regardless of how it ends.