This one is really a mix. There are lot of different puzzle techniques.   This one  can be done straight gematria and give a decent result.  First sentence: "The Wall is being built and is well under construction."  T=20=2.  W-23.  23+2=25.   25=B-H-O Last sentence:  String 3.  F D O F N     F D O F N 45-45 FF DON  FF DON DON = 33= F FF FF FF  In this tweet he also refers to Obama in three or four other ways that are not strict conventional gematria.  44, 8, H, BO, 25, 52 are also present. Some of the references in this tweet use lower case and upper case combinations.I understand that any single reference doesn't mean much. But when a bunch of them are all present in a short tweet, that changes the odds considerably.    But remember this tweet is a "throw-away", the visible subject is baloney and the hidden stuff is basically just confirms the subjects of recent tweets.   My feeling is that this tweet is just Trump trolling the opposition and thumbing his nose at them. For example "2-2-3 LOSER Q" or "BBC LOSER Q".   This is my decode of the "2nd string". I think he is just  trolling.  There is no new information in this tweet that was not sent in code prior.