The issue most important to me is the establishment of socialism, but setting that aside, you’re missing the point. This doesn’t represent rapid movement, it represents a rhetorical shift from a party that needs to sort of pretend to care what any of its supporters think to reduce the extent that they are hemorrhaging support. It is unlikely that the dems will actually “change their position on Israel” to something half-unconscionable until Israel’s condition has decayed so rapidly that the old position is irrelevant, which doesn’t actually represent a change in position because they would still support Israel if it was still viable.