Not just key, but absolutely critical. Every single maga voter is going to turn out, and gerrymandering gives them a huge advantage as will the corrupt scotus. There will also be voter and voting fraud in favour of maga because if they win it doesn’t matter. There will also be evidence found of democrat voting fraud, so that they can claim both sides are the same.
The only thing that will win this for the dems is overcoming apathy and voting in utterly overwhelming numbers, particularly in swing states.