President Bush said Tuesday that rival John Kerry (search) is blocking lawsuit restrictions that would help generate new jobs.

"I understand my opponent changes positions a lot, but for 20 years he's been one of the trial lawyers' most reliable allies in the Senate," Bush told thousands of supporters at an outdoor rally.

Bush, campaigning in suburbs of Kansas City that he won four years ago, said Kerry has consistently voted against legal changes that would protect workers and businesses.

"His fellow lawyers have responded with millions of dollars in campaign donations," said the president.

Bush said that "ending junk lawsuits" is necessary to create more jobs and that "the cost to our economy of litigation is conservatively estimated to be over $230 billion a year." Kerry running mate John Edwards is a personal injury lawyer.

The president was campaigning by bus Tuesday in Missouri, where a recent bounce in public opinion polls has the state leaning his way. Bush's latest visit to the state is the 21st of his presidency and his eighth this year.

Missouri has gone with every presidential winner but one in the past century. Bush narrowly won Missouri in 2000 by 79,000 votes out of 2.3 million cast.

Bush was also speaking Tuesday at the Missouri State Fairgrounds in Sedalia and at a county fairgrounds in the college town of Columbia. He made a Labor Day appearance in the southeastern town of Poplar Bluff near the Arkansas state line.

Voters in the areas of Lee's Summit and Sedalia overwhelmingly supported Bush four years ago, while he lost the county containing Columbia and the University of Missouri by less than 400 votes.

Kerry has made half a dozen trips to Missouri, most recently a month ago as part of a cross-country trek with running mate John Edwards following the Democratic convention.

One way for Kerry to win Missouri is a huge voter turnout in heavily Democratic Kansas City and St. Louis, a task that may be complicated by friction within the party.

Political analysts point to lingering bitterness in the party's ranks over a primary election that ousted incumbent Democratic Gov. Bob Holden, creating uncertainty over turnout prospects in November.

"I wouldn't say it's turmoil, but there's a certain lack of party unity that raises questions about getting behind the top of the ticket," said George E. Connor, associate professor of political science at Southwest Missouri State University.