But the op-ed, compounded by Woodward’s book sourced to numerous current and former White House officials, has left Trumpworld feeling under siege.
If you purchase or obtain something (e.g. kitchenware) from someone, and that person is known, then you can say that you source the kitchenware from that person. For example, 'We sourced the organic pork from a farm near Geelong'.
Someone has provided something (e.g. information), but you do not know who that person is. If you can trace that thing back to that person, you can say that you have sourced that thing back to that person. For example, 'We have traced the rumour back to a journalist in Sydney'.
So, the two terms are not the same. Sourced from is usually used when the source is known and you know you can go to the source and get what you want. Sourced to is usually used when the source is not known (and probably does not want to be known) and you have to search or investigate to find the source.