CRAWFORD, Texas (Reuters) - President Bush starts his "working vacation" on Wednesday by campaigning for a Mississippi Republican tussling with a two-term Democrat over a district near the hometown of bankrupt WorldCom Inc.

Leaving his Crawford, Texas ranch less than 24 hours after he got there, Bush planned to stress economic security, pension protections and the high cost of medical malpractice lawsuits during a one-day visit to Jackson, Mississippi.

He will also raise campaign funds for Rep. Charles "Chip" Pickering, a three-term Republican forced into a tough race against two-term Democrat Rep. Ronnie Shows when Mississippi lost one of its congressional seats after the 2000 census.

The visit takes Bush within hailing distance of Clinton, Mississippi, the headquarters of long-distance telephone and data services company WorldCom. A huge accounting scandal at WorldCom has made the company's name a byword for investors' anxieties and helped build momentum for the corporate reform law Bush signed last week.

The struggling economy and the fallout from the accounting scandals could prove a potent weapon for Democrats in the Nov. 5 elections, which Bush hopes will allow his fellow Republicans to keep control of the U.S. House of Representatives and regain a majority in the Senate.

Bush plans to use his 25-day vacation to make a series of political appearances for Republicans across the country and to stress -- particularly in an Aug. 13 economic forum in Waco, Texas -- that he is doing everything he can to create jobs.

The race between Pickering and Shows is expected to be an extremely close fight for Mississippi's redrawn third district, which is near, but does not include, Clinton.

Bush's visit, which will include a speech at a local high school, a fund-raising lunch and a round-table discussion on the economy, guarantees Pickering a day of media exposure as well as campaign money.

Shows plans to attend the high school speech, his campaign spokesman Troy Colbert said, and will then hold a rally near a Presto Manufacturing Co. plant in Jackson, which is expected to close in November and transfer its jobs abroad.

Bush, who spent most of his vacation last August at his 1,600-acre (650-hectare) ranch, is particularly sensitive to suggestions that he is taking it easy at a time of war and economic uncertainty.

As a result, the White House has scheduled visits to 15 cities during his vacation to help Republican candidates and promote Bush's agenda on education, trade and the economy.