I think they just assumed Trump would appeal and easily win. But the impact would be what they wanted - him having a criminal felony conviction hanging over him during the election. What happened afterward was not their concern.
But too much of the country knows lawfare when they see it. It backfired.
I think they’re calculating the over-and-under on leaving Trump as a “convicted felon” with a suspended sentence vs the backlash that would result from sentencing him to jail time.
This has always been a political prosecution, everything has been to maximize political damage to Trump’s candidacy.
Guarantee that polls and political consultants will have a bigger impact than legal scholars.