WASHINGTON – The roughly $800 billion stimulus package moving through Congress could create as many as 286,000 jobs in Texas, according to an estimate released Tuesday by the White House.

The figures came out on the same day that senators attempted, but failed, to boost highway spending from $27 billion to $40 billion in their version of the stimulus.

Economists caution that employment projections are inherently imperfect, as the White House study's authors noted when they wrote that their estimates "are subject to significant margins of error."

But if it comes to pass, the legislation could help cushion Texas against expected job losses over the next two years, according to economists. Texas created 153,600 jobs in 2008, but State Comptroller Susan Combs said recently the state can expect to lose about 111,000 nonfarm jobs during the first nine months of 2009.

"She was probably being optimistic," said Bernard L. Weinstein, director of the Center for Economic Development and Research at the University of North Texas. "It appears the 286,000 jobs might just offset the anticipated losses over the next two years."

President Barack Obama's administration is ramping up its public case for the stimulus, which passed the House last week but needs some Republican support to pass the Senate.

Lawrence H. Summers, director of the White House Economic Council, said Tuesday that the stimulus and the revamped approach to what remains of the $700 billion bailout "offer the best prospect for containing the economic damage."

"Make no mistake, though," Summers said. "These problems were not created in a day, a month or a year, and they will not be solved in a day, a month or a year."

Republicans argue the bill should include more tax breaks and less direct spending. They argue it won't create the number of jobs advertised by Democrats.

"I don't see how those numbers are going to be real," said Rep. Kevin Brady, R-The Woodlands. "Most of this [spending] is going to be spread out over the next three to five years."

The White House's study, released Jan. 10 but without the state-by-state job figures, projects the legislation would create 3.6 million direct and indirect jobs nationwide. Indirect jobs are positions that can be attributed to economic activity, such as purchases of construction material, that result directly from the stimulus.

The 3.6 million jobs include 459,000 in energy, 377,000 related to infrastructure and 244,000 in health care, according to the study.

White House officials said their estimates were derived from a stimulus "just slightly over the $775 billion" that was originally discussed. The House bill, passed last week, costs $819.5 billion. The Senate's version is $888 billion.