The reason that the level of attack was unprecedented was simple: the MSM was in the middle of a narrative that there was Trump remorse that was going to be proven by the special elections and then the 2018 mid-term.
However, prior to the Alabama special election, there was the Georgia 6th Congressional District special election. That was an unprecedented election for a small House district, with Hollywood pouring millions of dollars into Democrat Jon Ossoff (who didn't even live in the district he was running for). Handel won, but lost in the 2018 mid-term.
The other early 2017 special elections to fill Trump appointment seats went to Republicans in Kansas, Montana, and South Carolina. The Georgia 6th race was supposed to be the tide-turner.
When it didn't happen, the tide moved to Alabama.
-PJ
Also, i've noticed you generally have a quite good background understanding of political events, and astute perception as well.
Moore was incidental to the forces in conflict there. They just got lucky in the fact that so many people were willing to believe made up lies by kook women at the time, and it gave Republican establishment types an excuse to ditch someone they would view as a thorn in their side.
Washington DC doesn't want reformers. They want "business as usual" types.