A Commentary on the New Testament prepared by The Catholic Biblical Association in 1942, page 84, offers the following on Matthew 11:12:
12f. Similar words in Luke 16:16, but probably in a difference sense. The exact sense of this difficult passage is disputed. Either: (a) Since the Old Dispensation came to an end with John, the kingdom of heaven, i.e., the New Dispensation, has been enduring violent assault, in Greek literally “is being violated,” i.e., is being attacked by those who refuse to accept the change, and the violent, or “the violators,” have been seizing it by force, in Greek literally “are plundering it.” Or, (b) Because the Old Dispensation passed away with John, men are now rushing with violent enthusiasm to get into the kingdom of heaven, the New Dispensation, and they who rush through the crowd with force lay hold of the kingdom of heaven for themselves. The first opinion seems to fit the actual historical circumstances much better than the second. But it is to be noted that the Rabbis interpreted Mich. 2, 12f in the sense that, when the Messias would come, there would be a violent tumult of men jostling one another in an effort to get into His kingdom. The use of the text by ascetical writers in the sense that only they who do violence “to themselves” can enter the kingdom of heaven, would seem to be a mere accommodated sense.