What domestic political and security concerns would drive Bibi to go to war with Hezbullah in the month leading up to the U.S. election? This conflict is a year old, why the sudden rush to war?

Because the conflict is a year old, and has not reached any satisfactory endpoint for Israel.

The argument has long run that it is in Netanyahu's personal best interests to keep the war in Gaza going, because it forestalls his reckoning on all of his domestic political problems (not least the massive security failure that allowed the 10/7 attacks in the first place). The presumption is that as long as the war is ongoing, he can deflect an accounting on those other issues. That's probably true, but only to an extent - if the war footing reaches a de facto stalemate or natural pause, he's going to be vulnerable. Netanyahu needs progress - or at least movement or uncertainty - to keep everyone from considering the possibility of a change at the top.

Plus, Israel has been facing somewhat of a two-front conflict for a while now. They evacuated several tens of thousands of people from the north, basically abandoning Kiryat Shmona and surrounding cities near the Lebanese border, and had to station a non-trivial force up there to deter Hezbollah attacks in support of Hamas. There's been no progress on getting that combat zone under control, either.

IMHO, the relevant date driving this isn't November 5, but October 7. We're coming up on an anniversary that's going to have profound political and emotional significance for the Israeli electorate. Netanyahu almost certainly wanted to go into that with some military momentum, which he wasn't going to get in Gaza. Hence, Hezbollah. Far more significant than whatever happens with the U.S. election.

As I've said before in other contexts about the conflict, it's not about us. Hamas didn't care who the U.S. President was when they planned their attacks, and I highly doubt that Netanyahu gives much weight to the U.S. in making decisions as momentous as whether to escalate war with Hezbollah.