MONDAY'S U.S. Supreme Court decision on Arizona's controversial immigration law would affect about half of the anti-illegal-immigrant bills pending before the Pennsylvania Legislature, says one close observer.

"Half could be a big problem if they were to pass," said Nadia Hewka, an attorney at Community Legal Services of Philadelphia and chairwoman of the board of the Pennsylvania Immigration and Citizenship Coalition. The bills would likely be challenged, then struck down, she said.

The other Pennsylvania bills touch on issues that are not covered in Monday's Arizona decision, she said. However, she added that they, too, could be affected by the "spirit" of Monday's decision because the overall message is that federal law trumps state law.

In its highly awaited decision, the top court struck down three parts of Arizona's law, but unanimously ruled that its centerpiece provision could go into effect. That portion of the law, which the court said could still face legal challenges, requires law enforcement to check the immigration status of people suspected of being in the U.S. illegally, if they are first stopped for another reason, such as a traffic or other violation.

With this ruling and another from last year, the Supreme Court provides a "very narrow window" for "state action in response to illegal immigration," said Jan Ting, a Temple University professor who teaches immigration law.

In Pennsylvania, about 20 anti-illegal-immigration bills have been pending in the Legislature, with a few moving forward last week and at least one that could make it to Gov. Corbett's desk by the end of this week, just before the summer recess.

Pennsylvania's proposed version of Arizona's mandate requiring law enforcement to check on a person's immigration status after a legal stop, House Bill 801, has not yet been voted on.

Ting pointed out that other Pennsylvania bills could get the green light based on a Supreme Court decision last year, Chamber of Commerce v. Whiting, that upheld a different Arizona law. That decision allows the state to yank the licenses of employers who knowingly hire illegal immigrants and to mandate that employers use the federal E-Verify program to check employment eligibility.

In Pennsylvania, Senate Bill 637, which would require an employer to prove that it participates in E-Verify before being awarded a public-works contract, has passed the Senate and could be voted on in the House this week.

The bill that has progressed the furthest is Senate Bill 9, which would require people to show proof that they are legally in the U.S. before receiving public benefits. It previously passed the Senate and passed the House on Thursday; it is now before the Senate again because the House made amendments to it. Corbett is inclined to sign it, a spokesman said Monday.

Ting said Monday's decision and last year's Whiting ruling do not touch upon public benefits.

A divided Supreme Court struck down three provisions of Arizona's law: those making it a state crime for immigrants who fail to carry their immigration papers, making it unlawful for an illegal immigrant to look for work or perform a job, and allowing police to arrest suspected illegal immigrants without warrants. n

Contact Julie Shaw at 215-854-2592 or shawj@phillynews.com.