Pennsylvania Lt. Gov. John Fetterman campaigns for U.S. Senate at a meet and greet at Joseph A. Hardy Connellsville Airport on May 10, 2022 in Lemont Furnace, Pennsylvania.
CNN  — 

The Senate playing field has narrowed in recent weeks, with both parties focusing heavily on Georgia, Nevada and Pennsylvania as the three races most likely to decide which party has the majority come January 2023.

Picking which race is most critical of those three is a tough task. But for my money, it’s in Pennsylvania, where Lt. Gov. John Fetterman and Dr. Mehmet Oz are competing for the seat being vacated by retiring GOP Sen. Pat Toomey.

Why do I see Pennsylvania as the first among equals? A few reasons:

1) Pennsylvania could well be the biggest battleground of the 2024 presidential race – especially if Joe Biden and Donald Trump run again.

2) Oz is a candidate directly out of Trumpworld’s central casting. A longtime TV doctor and celebrity, he won the primary thanks to an endorsement from the former President. Now the question becomes whether Oz’s style of conservatism can sell in a general election.

3) Fetterman is an unapologetic liberal. Rather than hedge those positions or hide them in a general election, he’s leaned into them. That’s a blueprint liberals have long argued can be successful, even in a swing state like Pennsylvania. Fetterman’s candidacy is a test case for that theory.

4) Both national parties are heavily invested in this race – testing messaging for the inevitable fight to come in 2024.

What’s clear about the race is that Fetterman led by mid-to-high single digits for much of the spring and summer as Oz was battered in a primary that he narrowly won – and struggled to united Republicans even after he became the nominee.

But of late – thanks to a coordinated attack on Fetterman’s record on crime and lingering questions about his health following a stroke he suffered in the spring – Oz has crept back.

The Cook Political Report with Amy Walter, a nonpartisan campaign tipsheet, shifted its rating of the race to “lean Democrat” roughly six weeks ago. But on Tuesday, the rating moved back to “toss up.”

Senate editor Jessica Taylor explained:

“In conversations with several GOP strategists and lawmakers – who a month and a half ago had begun to put the Keystone State in the loss column – this has emerged as a margin-of-error race that they once again see winnable. Republicans and Democrats alike admit the race has tightened and that Pennsylvania could be the tipping point state for the Senate majority.”

So, with exactly five weeks left in this campaign, we have a tie (or something close to it) in a critical swing state between two candidates who represent drastically different visions of what the future of the country should look like.

That seems pretty important to me.

The Point: The fight for Senate control now seems very likely to come down to just a handful of races that are nip and tuck right now. And none is more important than Pennsylvania.