The argument wasn't that, "So-called progressives can keep telling themselves they are the majority". It was that, "In competitive districts, Democrats were hurt by the radicalism of the DNC’s national brand. In safe districts, pandering to the radicals can help boost turnout since Democrats don’t need to worry as much about losing moderate votes.".
This is false. Democrats got to run a moderate platform all across the country, from Senate races to competitive districts. Blaming progressives is just your opinion, not based on any data point or fact available or relevant at this point.
Iran is closer to a nuclear weapon as a direct result of JCPOA's dissolution, and it does matter. Nuclear proliferation is the single greatest threat as far as I, and many others, are concerned. Especially in a region as irresponsible and trigger happy as the Middle East. Iran's activities in the region are an entirely different issue, and one I have far less interest in. If we are concerned about Israel's security, I'm more than happy to support selling weapons to Israel, but I don't consider Israel to be under serious threat. It's a powerful country. Terrorism and other interior concerns are the responsibility of Israel, not United States.
Moreover, I have far less sympathy for countries like Saudi Arabia, Qatar, and U.A.E., than I do for Iran. I have absolutely no interest in supporting countries that are continuing the humanitarian catastrophe in Yemen, and are continuing to fund extremists that threaten the Western world, rather than the squabbles in Middle East. Iran is not the problem. It is one of the problems. Alongside Pakistan, KSA, and U.A.E. In fact, Iran is on the bottom of that list as far as I'm concerned, as Iran's activities are limited to their immediate neighborhood rather than to places like Afghanistan or extremist groups like ISIS.