Using ridicule to score their points, George Bush is denigrating Michael Dukakis's rival presidential campaign as a "magical mystery tour" even as Dukakis belittles Bush's experience and his choice of a running mate.

Stumping for votes on opposite ends of the country, Bush was keeping up his full-court press in California Wednesday, while Dukakis hoped a speech at Georgetown University in Washington, D.C., would cap his new focus on national security.Both men had interest in a day trip by President Reagan to campaign for Bush in Missouri. The president, too, has waded into the rhetoric of ridicule in a bid to promote his loyal vice president over the Massachusetts governor.

With the Nov. 8 election less than eight weeks away, any advantage in voter perception can be profitable to the candidates. Two national polls published today confirmed the closeness of the race with an indecisive electorate.

Late Tuesday night, Dukakis reflected on the loss of his once-large lead over Bush and told the Congressional Hispanic Caucus in the nation's capital, "July was our month; August was their month; and it's now September.

"We have eight weeks to go today, eight weeks in which to usher in a new era of economic greatness in this country in which all our citizens are involved - and I mean every single citizen in every single community in this country," he said. "That's what this campaign is all about."

Bush, in Chicago earlier Tuesday, countered Dukakis's economic message by warning business executives of dire consequences if they deviate from U.S. economic policy of the last eight years.

Calling Dukakis a "pessimist" bent on retreat, the vice president suggested the three-term governor would embrace higher taxes even though he has said he would raise them only "as a last resort."

"The surest way to kill the recovery is to raise taxes," Bush said.