PHILADELPHIA — Lyn Kirshenbaum understands why President Obama and Congressional Republicans keep exchanging roundhouse swings over health care and federal spending. Politics is a brutal business.

What she does not understand is why she is the one who is black and blue.

Ms. Kirshenbaum, a 61-year-old policy specialist at the Department of Housing and Urban Development here, is among more than 800,000 workers furloughed from federal payrolls since a governmentwide shutdown began Tuesday. Assuming it continues, her next paycheck will include only six days of earnings instead of the usual 10.

That is not all, however. Ms. Kirshenbaum says she has lost a week of pay since intractable disputes over federal spending triggered the so-called sequester last March, forcing agencies to furlough some workers. Nor has she had a raise in three years; Mr. Obama, under fierce pressure from Republicans, suspended raises for executive-branch employees in 2010.

She and other federal workers say they feel like collateral damage in the continuing fiscal and ideological wars between the White House and its political rivals, swept up in a conflict fought by rules they cannot fathom, in places that frequently have nothing to do with the issues at stake.