President Joe Biden will visit Philadelphia Tuesday to speak about voting rights, resuming his push for one of Democrats’ top priorities and taking on an issue that has roiled politics in Pennsylvania and nationally.

Biden will deliver a speech on “actions to protect the sacred, constitutional right to vote,” the White House said .

No further details were immediately available.

Biden’s visit comes weeks after Democrats saw their sweeping voting rights bill stifled in the U.S. Senate, and as they try to push back against a number of states in which Republican legislatures and governors have enacted laws making it harder to vote.

It also comes days after State Sen. Doug Mastriano (R., Franklin), a likely gubernatorial candidate and a leading election denier in the state, asked Philadelphia and two other counties to turn over election-related equipment and materials “needed to conduct a forensic investigation” of the 2020 election. Mastriano threatened subpoenas if the counties don’t comply, the latest step in a long-running effort to cast doubt on the outcome based on debunked conspiracy theories and lies.

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Voting laws have become one of the central battlegrounds in American politics, and Biden has vowed to keep pressing the issue after his party’s massive voting bill failed along party lines in the Senate. It’s a particularly salient concern to some groups heavily represented in Philadelphia, including voters of color and lower-income voters, who could be disproportionately affected by proposed restrictions spreading across the country.

Republicans, often spurred by a litany of false claims about the 2020 election, argue that elections are too vulnerable to fraud. But independent research has long made clear that voter fraud, especially voter impersonation, is infinitesimally rare. So has every serious review of the 2020 results.

In Pennsylvania, GOP lawmakers have also criticized the procedural changes that Democratic Gov. Tom Wolf’s administration instituted in 2020 amid the pandemic, as well as ones imposed by the Democratic-controlled state Supreme Court, arguing they went well beyond state law.

Courts have rejected almost every GOP challenge to those procedures.

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Republicans also point to the vast changes Democrats proposed in the Senate bill that stalled last month, saying it amounted to a federal takeover of election procedures, and criticizing its massive taxpayer financing for campaigns, part of a push to reduce the influence of big donors.

Democrats say the GOP proposals are aimed at suppressing groups that vote heavily Democratic. They have since turned their attention to a more narrow voting rights bill, one that includes a voter ID requirement — though Senate Republicans seem likely to reject that plan as well.

Biden has made regular visits to Pennsylvania, a critical battleground, including March stops in Delaware County to promote his $1.9 trillion stimulus bill and Pittsburgh to unveil his infrastructure plan, and visiting 30th Street Station in April to mark Amtrak’s 50th anniversary.