Who Says What Is “Realistic”?

From an article by Richard Morin and Claudia Deane, “Support For a War With Iraq Grows After Bush’s Speech,” in today’s Washington Post:

Support for war is growing even though most Americans are realistic about the consequences. Two-thirds of those interviewed said they expect “significant” numbers of U.S. military casualties if the United States attacks Iraq. Less than one in five — 19 percent — believe the conflict would be over in a “few weeks,” while 32 percent say it would probably last several months, and 45 percent predict that it could continue for a year or more.

Excuse me, but how do the Post’s pollsters know what course the war will take and hence what is “realistic”?

Say What?