Who are the realists?

Michael Barone asks whether the leaders of the the Iraq Study Group, James Baker and Lee Hamilton, are really "realists":

Baker and Hamilton have been labeled foreign policy "realists" in news stories and columns in the run-up to the release of the ISG report. But it doesn't seem very realistic to expect that we can get regime change in Iran and Syria through negotiations. Nor does it seem very realistic to expect that negotiations between Israel and Palestinians can reach a mutually acceptable solution when the Hamas government rejects Israel's right to exist.