MOUNT PLEASANT, IOWA ? Iowa Gov. Tom Vilsack announced his candidacy for the Democratic presidential nomination Thursday, positioning himself as a Washington outsider with heartland appeal.

Vilsack also emphasized the nexus between oil dependence, national security and the economy, saying he would give high priority to weaning the nation off foreign oil and promoting alternative energy.

“Energy security will revitalize rural America,” Vilsack told more than 500 cheering backers in the small town where be began his political career as mayor. “Energy security will allow us once and for all to remove and reduce our dependency on foreign oil from foreign countries that do not like us.”

Taking aim at President Bush, Vilsack said: “We have in the White House a president whose first impulse is to divide and to conquer, who preys on our insecurities and fears for partisan gain … “

Instead, Vilsack, the first Democrat to formally enter the race, vowed to have “the courage to create change” and resist the “endless partisan debates.”

In an era when voter unhappiness with corruption and partisan wrangling in Washington is especially high, political analysts said Vilsack is particularly well-positioned as a Midwestern governor to run for the White House as an outsider.

Nevertheless, Vilsack has a low profile outside Iowa and even he acknowledges his candidacy is a long shot.

Vilsack, who is finishing his second term, headed out quickly after his announcement for events in New Hampshire, South Carolina, Nevada and other states holding early tests of strength in the nomination contest.