That is simply not true. Facebook rate-limited apps for exactly this reason. Additionally, although it was technically possible, the TOS did not allow mass-scraping of friend data for any purpose, much less political purposes. Facebook monitored and routinely banned apps long before they ever accessed the data of even a few million friend profiles, let alone 190 million of them. That's why, according to Obama's own campaign manager, Facebook was "surprised" but then decided not to ban them - which they would have done to any other app.
the data was used for political microtargeting (in violation of FB's TOS)
Which is precisely what Obama did.
If you know of any evidence that Obama's campaign broke either the law or FB's ToS, please let me know.
See above.