(Columbia-AP) Jan. 29, 2004 - Democratic presidential candidate John Kerry officially picked up a key endorsement Thursday morning from Sixth District Congressman Jim Clyburn, South Carolina's top black Democrat.

Clyburn told ABC's "Good Morning America" he is backing the Massachusetts senator. Announcement of Clyburn's pending endorsement came Wednesday morning. Kerry and Clyburn later made a joint appearance in Columbia on Thursday morning.

Kerry also stopped at Midlands Technical College Monday to talk about his plans for preserving American jobs. He says he will stop the flow of American jobs to other countries, so students in American colleges have a career to look forward to.

The endorsement comes just before the February 3rd presidential primary in South Carolina, where up to one half of the voters could be black. University of Virginia political scientist Larry Sabato says the black vote is critical in South Carolina. Sabato says Clyburn's endorsement will have great influence.

Clyburn says Kerry has a plan to help create jobs in places like South Carolina. South Carolina has lost thousands of manufacturing jobs in the last ten years. Kerry wants to close tax loopholes for companies that move overseas and reward companies that create new jobs in America. Clyburn says Kerry has positions similar to Missouri Representative Dick Gephardt.

Clyburn originally backed Gephardt, who withdrew from the race after a poor showing in the Iowa caucuses. Clyburn's support had since been sought by all the remaining Democratic hopefuls.

Clyburn says he's been looking for a candidate with strong ideas about job losses, health care and personal security. The state's senior Democrat, US Senator Ernest "Fritz" Hollings, came out in support of Kerry last week.

The latest South Carolina poll shows 18 percent of likely voters were undecided.

updated 3:29pm by Chris Rees