In missive to Netanyahu and Gantz, Warren, Sanders, Durbin, Kaine and others say move would 'betray our shared democratic values'

While party is unified in opposition to Israel extending sovereignty to settlements and Jordan Valley, it's splintered over how harsh the response should be if Netanyahu goes ahead

Former US diplomats and Mideast experts say that time is working against the proposal as the US election campaign will be in full swing by the time Israel has a government