This is the day that should mark the beginning of the end of the torturous presidency of Donald John Trump. But replacing Trump with Joe Biden is an entirely insufficient goal for a moment in history so perilous as the one in which the United States’ 59th quadrennial presidential election is being conducted. This is also the day when Mitch McConnell’s vice grip on the United States Senate can be broken.

Ending Trumpism is vital for the country’s future. But so is ending McConnellism.

How? If Democrats depose Trump but McConnell remains Senate majority leader, Biden will begin his presidency as a lame duck. The former vice president will have the position he’s been seeking since the mid-1980s, but he will lack the power to govern in the decisive manner that is required at a critical juncture when the country is wrestling with a resurgent coronavirus pandemic and the mass unemployment that extends from it, when the demand for an end to police violence and systemic racism must finally be addressed, and when the climate crisis grows more severe with each passing hour.

Former President Barack Obama summed it all up while he was campaigning Monday in Georgia—the only state that will decide two Senate races today—when he declared:

If [Joe Biden and Kamala Harris] are going to deliver the change that we need—getting this pandemic under control, restarting our economy, protecting our health care, protecting our planet, reforming our criminal justice system, giving every young person an equal chance—then they’re also going to need a Senate that actually cares about those things. So, Georgia, not only can you put Joe and Kamala over the top, you can be the state that gives us all a better chance because you’ve sent [Democrats] Jon Ossoff and Rev. Raphael Warnock to the United States Senate.

Obama, who knows a thing or two about the extent to which a Republican Senate can obstruct a Democratic president, was reminding voters of a reality that is too frequently neglected in a media calculus that places too much emphasis on the Executive Branch and too little on the Legislative.

The fundamental political truism of this divisive moment is that anyone who imagines a Senate majority leader Mitch McConnell would give a President Joe Biden an inch is delusional. It’s not just that McConnell is a wild-eyed obstructionist. Even if the Kentuckian were inclined to negotiate with his former Senate colleague, he leads a Republican Caucus that is now so packed with right-wing extremists that any sign of cooperation would spark an ideological revolt.

So on this Election Day and in the days that follow, I’ll be watching the presidential contest that has, necessarily, taken center stage—and that will not be settled until Trump and his supporters stand back. But I will be keeping just as close an eye on the Senate races that will define the scope and character of a Biden or Trump presidency. Should Biden prevail, the Senate races could also determine the makeup of the new administration, as the names of a number of Democratic senators have been floated as potential nominees for cabinet posts: Vermont Senator Bernie Sanders as labor secretary, Massachusetts Senator Elizabeth Warren as Treasury secretary, Delaware Senator Chris Coons or Connecticut Senator Chris Murphy as secretary of state.

Both Sanders and Warren come from states with Republican governors who could appoint interim successors before a special election. If the Senate is closely divided, their chances of joining the cabinet sink to roughly zero.

For Biden to start thinking about plucking cabinet members from the Senate, McConnell must be well and truly disempowered.

There are many routes, however, to that disempowerment.

Of course, I’ll watch tonight to see if, in the upset of upsets, Democrat Amy McGrath might actually convince a sufficient number of Kentuckians to toss McConnell out of the Senate. But that’s not the only way that McConnell could be derailed this year.

If Democrats win the presidency and finish the long count with a net gain of three seats, that will produce a 50-50 split in the chamber. Then Vice President Kamala Harris, as the new president of the Senate, will tip the balance to the Democrats. But this, too, would be an insufficient result for those of us who want a swift change of direction—or anything akin to a new New Deal. The next Senate will be organized on January 3, and Harris will not be sworn in until January 20. In addition, the California Senate seat that Harris now holds will need to be filled with an interim appointment by Democratic Governor Gavin Newsom.

So Democrats are really looking for a net gain of four seats and a clear 51-49 majority—or, because some Senate Democrats are more reliably progressive than others, the wider margin that could give a new majority leader, New York Senator Chuck Schumer, the flexibility he would need to lead on vital issues such as labor law reform.

Can they get it? Let’s start with some numbers. The current Senate Republican Caucus has 53 members, while the Democratic Caucus has 47 (45 Democrats and two independents, Sanders of Vermont and Senator Angus King of Maine). Twenty-three Republicans seats are up for grabs today, while 12 Democratic seats are at stake.

One Democratic senator, Alabama’s Doug Jones, is broadly seen as being vulnerable to defeat. Two others, Michigan’s Gary Peters and Minnesota’s Tina Smith, face serious challenges but look to be ahead.

If Jones gets beat, Democrats will need to win at least four seats. There are two races that analysts generally point to as likely pickups for the Democrats: the Arizona contest where challenger Mark Kelly has long led appointed incumbent Martha McSally, and the Colorado contest where former presidential candidate John Hickenlooper is ahead of incumbent Cory Gardner.

An additional six toss-up races are possibles for Democrats. The most likely pickups seem to be in Maine, where instant runoff voting should give challenger Sara Gideon the advantage over Republican incumbent Susan Collins, whose “moderate” act hasn’t been playing well since she cast the critical vote to seat Justice Brett Kavanaugh on the Supreme Court. But Democrats could also gain seats in Iowa, Montana, North Carolina, South Carolina, and in those two Georgia contests. The twist is that the Georgia contests could both end up in runoff elections held on January 5, 2020—two days after the new Senate is supposed to be seated.

What this means is that the makeup of the next Senate might not be decided until the last stages of the transition process. That’s not good for Biden, or for the country.

On the other hand, if Georgia were to elect Ossoff and Warnock today, a President-elect Biden would in all likelihood be able to forge his administration from a place of strength. That’s why former president Obama was in Atlanta on Monday saying, “Georgia could be the state. Georgia could be the place.”

He’s right that Georgia could be the place. But so, too, could North Carolina or South Carolina, Montana or Iowa. Or even Kansas or Alaska. For Democrats tonight, it is less a matter of where Senate seats shift than that a sufficient number of seats are flipped to oust McConnell as majority leader—because ending Donald Trump’s presidency isn’t enough. They also have to ditch Mitch.