Another Round of Presidential Debates

You could be forgiven for thinking the presidential election is just around the corner, instead of late next year. Debate season is well underway.  Last night, New Hampshire was the site of the third Republican debate so far. Earlier in the week, it was host to the second debate by the Democrats. Democrats elbowed each other, Republicans went after the Democrats, and pretty much everybody criticized President Bush. With a flock of contenders in both fields, what effect do early debates have on the long-term race?  Eighteen months before the election, what campaign strategies are emerging? Do debates have any effect on public opinion so early in the season? Will immigration and Iraq define the election next year?