Perhaps this may clarify the sentence:
'We recall, in special times, when we have stood briefly, but magnificently, united.'
So, 'recall in' is not a phrasal verb and so don't take it as one phrase. Writers sometimes omit commas to make writing smoother so as to reduce abrupt pauses or to control pauses - especially in public speech like in politics. It's likely that Carter wanted to emphasize 'but magnificently, united' and so pausing anywhere before by adding commas will reduce the speech effect of this.
Hope this helps.
