@ryan_landay As for margin, that may not be quite so true in US politics at this point. There is so much polarization that the marginal voters in the middle are pretty hollowed out. May be even more so in mid term election. Enthusiasm/turnout has gone way up in importance.
@ryan_landay至于利润率，目前在美国政治中可能不是这样。两极分化太多，中间的边缘选民都被掏空了。在中期选举中可能更是如此。热情/参与率的重要性大大提高了。