House Republicans' narrow majority could get even smaller if Democrats flip Santos' old seat on Tuesday

• New Yorkers will vote for who to replace former Congressman George Santos on Tuesday.
• Former Rep. Tom Suozzi is facing off against relative newcomer Republican Mazi Pilip.

House Republicans' narrow majority could get even smaller on Tuesday, potentially dooming their chances to impeach the first Cabinet secretary in nearly 150 years and handing the GOP another setback.

The special election to replace ousted Congressman George Santos has become an expensive slugfest for both parties. Polling shows former Congressman Tom Suozzi, who left Congress for a failed gubernatorial run, only narrowly leading Republican Mazi Pilip, whose campaign for the wealthy, Long Island district has been known for her scant public appearances. Republicans chose Pilip, a registered Democrat, largely for her lack of establishment ties. She currently serves in a part-time local office and is an Ethiopian-born Jew and Israeli Defense Force veteran.

Here's what else you need to know about the race.

Republicans could use a win.

Last week, leaders in both parties seemed to lose control of their rank-and-file in embarrassing ways. House Speaker Mike Johnson even complained about being outmaneuvered on a potentially historic impeachment vote for Homeland Security Secretary Alejandro Mayorkas, unable to account for a House Democrat being wheeled into the chamber.

A win in this district would also underline that the GOP can maintain a competitive edge in the nation's suburbs under the right circumstances. Republicans at the Nassau County level now control virtually every office, a striking reversal compared to when Suozzi was rising to Congress. The New York City-suburban district is the same territory that humbled Democrats at the local and national levels in 2022.

One vote could make a major difference in the House.

On a basic level, Johnson could use another seat. The speaker, who catapulted into leadership after Kevin McCarthy's historic ouster, complained recently how the GOP had effectively a one-seat majority. House Majority Leader Steve Scalise, who missed the Mayorkas vote due to health complications, is expected to return to Washington this week. Santos himself poked fun at his GOP colleagues, 105 of which voted in favor of kicking him out after a damning ethics report, when it became clear that the Mayorkas vote could fail.

Democrats have flooded the airwaves.

Democrats have spent more than $10 million to flip the seat, per Semafor. Their party too could use some good news after special counsel Robert Hur raised fresh questions about President Joe Biden's standing. Before the report came out, Suozzi said it would be unhelpful for the president to campaign for him. For her part, Pilip has declined to say how she voted in the last two presidential elections.

Republicans have spent over $6 million touting her compelling story and hammering Suozzi over immigration. Her actual campaign is relatively sparse. As The New York Times pointed out, she doesn't have a single person on its payroll.

Immigration has loomed over the race.

Pilip has tried to tie Suozzi to Biden's immigration policies. She has also used images of migrants in New York City, including footage of migrants beating police officers in Times Square to drive home the issue.

Suozzi has tried to tie Pilip to Santos. The former congressman has also tried to capitalize on former President Donald Trump's role in killing a bipartisan border-Ukraine deal that made some progressives uneasy.