LogFAQs > #969990342

The trick here is that the moderate Democrats and Republicans are not actually forming or joining a new party. They will continue to run in elections as Democrats and Republicans. Then, once elected, assuming that moderates end up with a majority of both houses, they form a coalition of moderates. If moderates don't end up with a majority of both houses they just act as Democrats and Republicans as usual. There should be very little risk of the extreme elements of the parties getting together and forming their own coalition in that scenario because they would never ally with the other extreme.