Pennsylvania last raised its minimum wage on July 9, 2006, when Gov. Ed Rendell signed a bill that gradually increased the state’s base pay from $5.15 to $7.15 an hour.

But the Legislature didn’t just give workers a $2 raise. Lawmakers also voted to preempt local municipalities from raising the minimum wage on their own.

That language was added in the Senate Labor & Industry Committee, which at the time was chaired by Sen. Joe Scarnati, R-Jefferson, who’s now president pro tempore of the chamber.

That change really didn’t matter for most municipalities, which are blocked from regulating the “duties, responsibilities or requirements” of private businesses by state law.

But it did affect preemption’s most popular target: Philadelphia.

Preemption is something that comes up during a number of hot-button debates in Pennsylvania, from gun control to paid sick leave. Below, we dive into what it is, how it’s used, and more.

What is preemption?

For the purposes of this explainer, preemption is when the General Assembly restricts or forbids a lower-level of government from doing something.

Pennsylvania is a home rule state, meaning municipalities can adopt a charter and have an established, elected local government. But under the state Constitution, the Legislature is still given the power to restrict a home rule locality’s actions:

“A municipality which has a home rule charter may exercise any power or perform any function not denied by this Constitution, by its home rule charter or by the General Assembly at any time.”

What makes Philadelphia so special?

Besides Gritty? Philadelphia is the only city of the first class in the commonwealth, because it has a population greater than 1 million. That means it has special privileges.

Perhaps most crucially, Pennsylvania’s first class city law does not prevent Philadelphia from regulating private businesses. Home rule municipalities (see: basically everybody else) are not allowed to “determine duties, responsibilities or requirements” of private businesses.

What about paid sick leave?

What a pointed question! Philadelphia enacted a law in 2015 that requires employers with 10 or more workers to provide paid sick leave. That’s kosher under state law. (More on that below)

Pittsburgh tried to do the same thing that year, but was quickly sued by restaurants and an industry group that claimed the city overstepped its home rule powers. Lower courts agreed that, under the state’s home rule law, Pittsburgh isn’t allowed to require paid sick leave for private employers.

In what may turn out to be a landmark ruling, the Pennsylvania Supreme Court in July reversed those lower decisions and ruled in favor of the city.

Justice David N. Wecht, writing for the majority, said the court needed to find a “middle ground” between allowing home rule municipalities to govern and preventing them from burdening private businesses.

It will take time for this decision’s full impact to be felt, but it’s safe to say it’s a pretty big deal.

So how has preemption been used in Pennsylvania?

In some really crucial ways.

The Legislature, for example, prevents all municipalities from passing local guns laws. Pittsburgh is again pushing the envelope on that front, with a number of laws passed in the wake of the Tree of Life synagogue shooting.

They include a so-called “red flag” law, which empowers family and law enforcement to petition a judge to confiscate firearms from a person deemed at-risk of harming himself or others. Democrats and suburban Republicans in Harrisburg have been trying to pass a similar statewide law for years, unsuccessfully.

Pittsburgh’s red flag law is set to go into effect in September.

In recent years, there have been pushes in Harrisburg to further restrict Philadelphia’s special powers. The city’s controversial soda tax was on the chopping block last year, as was its paid sick leave law.

Because of the July state Supreme Court ruling — which, in theory, would allow most home rule municipalities to pass paid sick leave — the latter may be a prime target when the General Assembly returns from summer recess this September.

Why are some lawmakers in favor of preemption?

In a word? Uniformity.

State Rep. Seth Grove, R-York, is one of the Legislature’s most vocal preemption advocates. This session, he’s re-introduced a bill that would “preempt local governments from passing labor policies which impact private businesses and their employees.”

“For decades, labor policy has been set forth at the state level. This led to a predictable economic environment and uniform workplace policies across the Commonwealth,” Grove said in a 2018 statement. “Of late, however, local governments have adopted local ordinances, creating a patchwork system of policy throughout the state.”

Is preemption unique to Pennsylvania?

Not at all.

A 2018 report from the National League of Cities found “aggressive moves by state legislatures nationwide to usurp local authority.”

According to the report, Pennsylvania is one of 28 states that preempts local increases in the minimum wage, while there are 23 states that preempt paid sick leave ordinances. The commonwealth is unlikely to join that list.

Even is a paid sick leave preemption passed both the House and Senate, Gov. Tom Wolf has in the past vowed to veto such a measure.