Israel’s ambassador to the United States was racing in and out of offices on Capitol Hill, trying to persuade lawmakers that the nuclear deal with Iran is a historic mistake. On the other side, liberal groups are ramping up the pressure. They’re warning of political consequences for Democrats who undermine the deal and they’re casting opposition as a vote for war. The lobbying fight is on for the accord that the US and other world powers just signed with Iran. Multimillion-dollar ad campaigns are getting under way by politically influential groups in each camp. Think tanks are releasing reams of reports. Nuclear weapons and foreign policy experts are testifying.