As a deliberative liberal rationalist and all that, I think one of the most important goals in politics is to improve the quality of public debate. Probably the only way to achieve this is to encourage more people to embrace these civic values, and self-identify first and foremost as citizens rather than partisans. For as long as politics is dominated by partisan radicals who care only about winning, there seems little hope of improvement. To encourage positive change, gutter politics must be roundly condemned. (And by "roundly", I mean to include their political allies, not just the opposition who suffered the slander in the first place.) There needs to be a public backlash against duplicitous politicians. Indeed, our whole political culture is in sore need of improvement.
The mainstream media are hopeless subjectivists. Reporters focus on political characters and power struggles, rather than assessing policies on their merits. So-called political "analysts" discuss whether the latest scandal will cost this or that political personality come the next great popularity contest. They see politics as sport; the top players, celebrities. There's limited normative analysis. (See Chris Dillow on the media's "fact fetish".) Few seem much interested in what policies would be best, impartially considered. But this is the only question here really worth asking! All else is mere spectacle.
We should reject the metaphor of politics as sport, along with those who peddle it. Chris suggests that "there’s little demand for high intellectual standards" -- we need to create that demand. We need more rationalistic analysts, who are willing to really engage with the issues, advance public understanding, and offer substantive contributions to the public debate.
In the public sphere, we should hold ourselves and our "allies" to the same high intellectual and civic standards that we rightly demand of others. Attempting to shut down dialogue, say by slandering the opposition as "traitors" or "bigots", is hugely damaging to civic discourse. (Of course, such accusations may sometimes be accurate and justified; the point is simply that they shouldn't be thrown about so carelessly as at present.) A little interpretative charity and good faith would go a long way. And a long way away is precisely where those who lack these civic values ought to go.