Money is pouring into the special election at New York’s Third Congressional District as groups look to send a message in what’s expected to be a hotly contested battleground in 2024.

With the special election in the district only weeks away, parties are turning up the steam in the spending race supporting Congressman Tom Suozzi and county legislator Mazi Pilip.

The most recent Federal Elections Commission filings show that outside groups have spent nearly $1.7 million supporting Mr. Suozzi and around $3.6 million opposing Ms. Pilip. Likewise, outside groups have spent around $155,000 supporting Ms. Pilip’s candidacy and around $742,000 opposing Mr. Suozzi.

While parties are expected to spend more ahead of the election, Republican committees announced a $2.3 million ad buy earlier this week. The big spending in the district raises the question as to why parties are spending so much.

In a practical sense, parties are forced to spend more because New York is among the most expensive press markets in the country. A political scientist at John Jay College, Susan Kang, tells the Sun parties are also hoping to send a message.

“It’s clearly an important race for both parties, and they’re both seeing it as a litmus test for 2024,” Ms. Kang says. “Whoever wins this is going to say, ‘See, we’re going to win the House.’”

Ms. Kang added that this sort of dynamic can set off a sort of  “arms race” where one party makes a major investment and the other party decides that they need to match them in turn.

Aside from the implications for 2024, both parties have a more immediate interest in winning the February special election — it could whittle down the GOP majority even more.

After 2022, Republicans enjoyed a slim 222-seat majority in the House, with Democrats sitting in just 213 seats. Since then, however, retirements have further slimmed the Republican ranks to just 217.

Should Democrats win the special election in New York, their caucus will hold 214 seats. In this scenario, just a handful of Republican absences — which could be due to sickness, medical appointments, or any number of things — could leave Democrats temporarily in the majority.

With the current rules of the House, Democrats could then file a privileged motion to vacate the chair and almost immediately oust Speaker Johnson. Congressman Steny Hoyer told the New York Times last week that, in this situation, “We’d elect a speaker.”

Besides the possibility that Democrats could seize a fleeting majority in the House, a win in February would give them a little more leverage in the House at a time when Republicans have already struggled to govern with their majority.