WASHINGTON — Health care, telecommunications, and defense industry workers are fueling President Obama’s reelection campaign.

Those industries were with Obama in 2008 after helping to bankroll George W. Bush’s reelection campaign in 2004, according to the Center for Responsive Politics, a Washington-based research group that tracks campaign donations.

‘‘It’s a sign that incumbents really attract a lot of money,’’ said Bill Allison, editorial director of the Sunlight Foundation, a Washington-based watchdog group that tracks money in politics. ‘‘Obama’s in the White House right now. The way you try to influence the administration is by giving to his campaign.’’

Democratic consultant Peter Fenn, who participates in a weekly conference call with Obama campaign officials, said the president’s budgets have not called for massive cuts in defense spending, although a deal struck to raise the debt ceiling last year could lead in January to more than $500 billion in automatic cuts during the next decade if Congress and the administration do not reach a new agreement.

The telecommunications industry has received broad support from Obama, whose stimulus bill included $6.9 billion to expand high-speed wireless Internet access.

As for health care, the administration worked with drug companies and hospitals in developing his plan and ‘‘they’re comfortable with Obama’s policies,’’ Fenn said.