Republican George Bush launched one of his harshest attacks to date on Democrat Michael Dukakis, denouncing his opponent for a "flawed world view" and "old-style '60s liberalism." The Dukakis camp suggested that the vice president's weakness in the polls prompted the "mudslinging."

Meanwhile, a pair of polls published Friday suggested the Democratic ticket would be hurt if Jesse Jackson were Dukakis' running mate. A USA Today-CNN survey indicated Dukakis has a clear lead over Bush - unless he picks Jackson as his running mate. And an ABC-Washington Post poll suggested Jackson's presence on the ticket would hurt Dukakis among key groups whose backing he needs to win in November.Both Bush and Dukakis looked ready for a long hot summer leading up to their respective parties' conventions. Although the post-primary, pre-convention period traditionally marks a lull in campaign activity, the two rivals are indicating they won't wait for formal nominee status to begin their battle.

"There's no reason to wait till the World Series to start swinging," said Bush, in Texas to address delegates at the state GOP convention on Thursday. "This is a new ball game - spring training is over."

The vice president criticized Dukakis' positions on a variety of topics, saying the Massachusetts governor would raise taxes, plague innocent taxpayers with IRS audits, weaken national defense, be soft on crime and put forth an isolationist foreign policy.

"My opponent is an articulate defender of a flawed world view," said Bush. "His views and values are too often ... out of the mainstream."

Dukakis campaign spokesman Leslie Dach said "it's clear that the vice president doesn't think his own record or vision can bring him the votes he needs in November."

"Given where George Bush is in the polls, I think it's no surprise that he's chosen to spend his time mudslinging and tearing down," Dach said.

A series of recent nationwide polls suggested Dukakis had the edge in a faceoff with Bush, with some surveys putting the lead in double digits.

The latest such survey, the CNN-USA Today poll, gave Dukakis a 6-point lead over Bush, 45 to 39 percent.

Dukakis became the certain Democratic nominee on Tuesday, when the final four primaries of the season gave him the delegates he needs for a first-ballot victory in Atlanta. Bush put away his GOP rivals months ago.

Three of those former opponents - Kansas Sen. Bob Dole, television evangelist Pat Robertson and Rep. Jack Kemp - were joining Bush at a Republican "unity conference" Friday in Denver.

And the Atlanta Constitution reported in Friday's editions that former Dukakis rival Tennessee Sen. Albert Gore Jr. is planning to endorse Dukakis, possibly during a Dukakis campaign trip through the South next week.

"It's really just a matter of time before there is an announcement by Senator Gore on what his plans are with respect to an endorsement and possibly releasing delegates," Mike Kopp, Gore's press secretary, told the newspaper.