But since it has been brought up, it's fun to look at McGrath's total failure against McConnell as the starkest example of the failed Democrat strategy of courting moderates and conservatives more than their base.
We can start with party ID: McGrath won Democrats (30% of respondents) 86 to 13, makes sense.
McConnell won Republicans (46%) 90 to 5, which makes sense and you might notice, is a much stronger lead on his base than McGrath had on hers, despite McGrath aiming to take votes away from his base, so there's a complete failure.
Finally Independents (25%), McConnell won 51 to 41, which is a pretty big washout and the other demographic that the Democrat party wants to tap so they don't have to listen to their left, dumped her too.
When we move to ideology (liberal, moderate, conservative), the numbers are similar with McConnel winning harder in his demographic than McGrath in hers, but the moderate axis is flipped with McGrath winning it 51 to 43, the closest we get to breathing life into the Democrat strategy. Of course we can see that the liberal turnout was small and the moderate difference wasn't that high, so the strategy didn't pay dividends.
There are a lot of other metrics you can dissect, but there's one last one I want to point out as being truly important here, where. McGrath won Jefferson County and nowhere else in the broad geographical sense. Her next best area was the area around northern Kentucky, which has Jefferson county (but is not included as part of this demographic, I presume) which she lost by 7 points. The only place she won was 18% of the overall vote and she lost the rest of the state by 7 to 52 points.
Centrists will look at this and say that's why blue can't win in red states. Instead let's look at Georgia. Ossoff vs Perdue. Ossoff isn't what anyone would call progressive, he's kind of a dud too, but he was dressed up better than McGrath, and there was a massive grass roots movement in the urban centers to propel him up.
So by party ID he did nearly as well with Democrats as Perdue did with Republicans, but there was a much higher Dem turnout compared to McGrath so that victory was more meaningful. Similarly, he did better with independents compared to McGrath, actually winning his share instead of losing it. Likewise in ideology he did better sucking votes away from his Republican opponent than McGrath did against McConnell, but further he won the moderate vote a whole lot harder than McGrath did (he won moderates by 29 points instead of 8).
So how did that happen? Ossoff still lost the rural areas, some as badly as McGrath did. But while McGrath only won in downtown Louisville, Ossoff won downtown Atlanta, but also the suburbs and stayed competitive in the surrounding areas. Ossoff's turnout in the urban center was higher than McGrath's and the areas surrounded that urban center (which despite being suburbs, is actually quite urbane) came out hard for him, as opposed to McGrath where the vote was depressed and thus went handily to McConnell. As we saw on the night of the vote, people had come out to drive the vote in Atlanta and it's area, not by promising to be electable, not by saying he was some fighter pilot, not by kissing up to Trump, but by putting forward strong people-centric promises of policy. That's what drove what the Democrats say is their strategy. We have a handy dandy comparison to show how effective it is and can pretty solidly conclude that going left (even pretending to) drives the core out to vote.
And this bares out in those other demographic statistics in the exit polls. In Kentucky the majority of the votes cast were rural and went to McConnel, in Georgia rural votes were the minority. In Kentucky the suburban votes were the minority and they went hard to McConnel anyway, in Georgia they were the majority and while they went to Perdue, it was by a much narrower margin to allow his much stronger urban vote to pull him ahead. Ossoff won the poor while McGrath lost them, in fact McGrath didn't win any demographic based on income (Funnily enough Ossoff also won with the rich, albeit narrowly, he only lost to the middle class because they're treacherous snakes). Ossoff won the young harder than McGrath, and turned out in greater numbers for Georgia than for Kentucky, burying the talking point that the young don't vote. Just ask them to and give them a reason to and they will. McGrath won the idologies of "Can unite the country" and "Has good judgement" and lost while Ossoff won those harder, but also the demographic of "Cares about people like me", which McGrath lost. Ossoff of course, won.
You can see this all cascade from starting in the urban centers and pushing out, driving at the bottom level not by appealing to moderates, but by making promises that will pull people to you, and that means making left friendly policies.