Up until last Friday, 10yr Treasury yields had consistently closed at 4.27-4.28 last week.  Now this morning, we're at 4.27-4.28 again.  That's the shortest way to explain that we're not dealing with a meaningful rally.  It's only impressive when considered against the weird, panicky starting point created by the weird, panicky sell-off on Friday. 

Another way to put this morning's move into perspective is to remember that a 10-12bp rally right now is equivalent to a 3-4bp rally during more normal times. As for justification, the approaches are limited to two options: shifting election odds and/or a reversal of a pre-weekend position dump that's now being reversed--probably a combination of the two.