Vice President George Bush won the "biggest come-from-behind horse race that we've ever had," according to presidential pollster Richard Wirthlin.

Wirthlin, who has conducted polls for President Reagan for the past 10 years, spoke Thursday to a group of communications students at Brigham Young University.The pollster said Bush's victory was so impressive because he trailed Democratic challenger Michael Dukakis by 20 points last August, and yet the president-elect won by eight points.

"For Dukakis there was a modest, almost immeasurble surge at the end (of the campaign), but it was just that - almost immeasurable," Wirthlin said. "One of the mistakes that Dukakis made early was that he said he was going to run a 50-state campaign. You must focus your resources on the critical key states," Wirthlin said.

Bush's campaign was successful because the United States is experiencing peace and prosperity, President Reagan is still popular, the vice president had good experience and he assured voters he would bring changes to government, Wirthlin said.

"The one thing that's clear is that there's a very important problem that almost always dominates presidential politics, and that's peace," he said. "One of the problems Dukakis ran into was first he claimed that he was a conservative and then he claimed that he was a liberal. The Willie Horton attack was designed to raise the issue of personal security and also to attack Dukakis as a liberal, and in that respect, it worked very well."

Wirthlin said there are several keys to effectively communicating with the public during a presidential campaign:

-First, it's important to limit campaign communication strategies to no more that five or six concepts. "The simpler, the better," he said.

-Candidates must focus their efforts on key states and people so they do not waste limited resources.

-Getting a message out frequently and dispersing it widely also are vital.

-And candidates should be sure of their facts and emphasize overall consequences rather than just issues.