Washington, D.C. ? The AIG employees who got big bonuses last weekend and now could face a 90 percent tax bill may feel they have been singled out for unfair punishment by angry lawmakers.

But they are not likely to win a court challenge if the bill becomes law, legal experts said Thursday, because courts have given legislatures broad leeway to raise and lower taxes without running afoul of the Constitution.

“The courts are very reluctant to strike down tax legislation,” said Edward McCaffrey, a tax expert at the University of Southern California’s Law School. “I think a tax this high and this targeted raises some difficult questions, but at the end of the day, I would bet a constitutional challenge would not work.”

The Constitution says, “No Bill of Attainder or ex post facto Law” may be passed. A “bill of attainder” singles out persons for punishment, while an ex post facto law adds an after-the-fact punishment for past conduct. But the Supreme Court has limited those provisions to laws that “inflict punishment,” mostly in the criminal arena.

The tax bill passed by the House Thursday did not name names. And it was broadened to extend beyond AIG.