WASHINGTON — In the next weeks and months, Lisa P. Jackson, the Environmental Protection Agency administrator, is scheduled to establish regulations on smog, mercury, carbon dioxide, mining waste and vehicle emissions that will affect every corner of the economy.

She is working under intense pressure from opponents in Congress, from powerful industries, from impatient environmentalists and from the Supreme Court, which just affirmed the agency’s duty to address global warming emissions, a project that carries profound economic implications.

The new rules will roll out just as President Obama’s re-election campaign is getting under way, with a White House highly sensitive to the probability of political damage from a flood of government mandates that will strike particularly hard at the manufacturing sector in states crucial to the 2012 election.

No other cabinet officer is in as lonely or uncomfortable a position as Ms. Jackson, who has been left, as one adviser put it, behind enemy lines with only science, the law and a small band of loyal lieutenants to support her.