It's supposed to be the final sitting week of US Congress for 2017 here in Washington, DC, but much of the conversation is fixated on what its two houses will look like in 2018. Roy Moore's shocking loss in the Alabama special Senate election and the resignations of Democrats Al Franken and John Coyers over sexual harassment allegations herald a number of 'known unknowns' in the congressional make up next year.

That's not to mention November's mid-term elections which will of course loom over most of 2018, influencing the direction of numerous policy debates. 

A Roy Moore win Tuesday would have been a particularly ominous portent for Democrats. Here was a man who many establishment Republicans thought much too controversial and publicly disowned even before he was accused of sexual misconduct with minors. In 2016 he was suspended as an Alabama Supreme Court judge for violating judicial ethics after instructing probate judges to defy federal court orders on same-sex marriage. He had also previously said that he believes homosexual conduct should be illegal. 

Despite initial reluctance, President Trump wholeheartedly endorsed Moore, even recording a robo-call for his campaign in its closing days. This is a loss for him as it is for his former chief strategist, Steve Bannon. Moore had called Bannon a "master strategist" and credited him for helping his campaign recover after the sexual misconduct allegations first surfaced.

Yet there will be many Republicans breathing a sigh with relief at this result. If the disgraced judge had made his way to Washington (and survived a Senate ethics probe), there was no guarantee he'd be a strong supporter of the party's legislative agenda. Moore owed nothing to the Republican Party and its leaders like Mitch McConnell. He also held views more extreme than some of its most socially conservative lawmakers.

Democrats too would be wise not to pop the champagne. November will be a fight not just for control of the Senate, but for the heart of the Democratic and Republican parties alike; centrist candidates will have to fend off those on the far-left and far-right from seizing control of their agendas as the nation finds itself increasingly polarised.