It would be far worse than anyone could imagine, even if all crucial infrastructure was shield, most major cities only have 3 days worth of food.
There are many untapped food sources such as peoples lawns, trees, animals. People also have "personal supplies of food" not everyone lives day to day, some people have weeks or more of food, also there are stockpiles of food. There are a lot of fat people in America also they can live for weeks or months without sizable food. Sure it ain't going to be nice but cities would actually INCREASE their food resources as a result and while there would be hardship people who stayed calm and organized should be able to in an orderly manner plant up short growth food crops. Dandelions are plentiful in most urban areas, and food is shipped in anyway. Think Dutch Famine 1944. The hysteria would likely exagerate the situation, and there would be a lot of potential chaos, but lets get serious they locked down Boston, they can lock down most any other major city in the US, and people will be looking to the government to "save them".
it will be medieval and barbaric.
The military, national gaurd, DHS etc. will lock down America, if required COOG operations will come into effect, and people will leave if there is no food locally. Its pretty simple. Lots of people will try to travel to unaffected areas You don't need electricity to store food You need gas or diesel to deliver it. Critial infrastructure will be a priority to put back online. Issues like data tracking will be issued, due to electronic logistics systems being effected, however, I think that in rough times people come together greater than ever. Sure preppers will be advantaged with having way less hardship than others, however overall damage will not be able to greatly eat into population or resource. Electronics go to the dump day in and day out. Its the manufacturing and resource points that matter. It will hurt the economy no doubt, it will cause problems, and it will be devestating but if areas that are critical infrastructure, and dangerous substances, mostly nuclear material facilities, CDC center in Atlanta and other labs etc.. get safely managed, it should be fine. What would make the problem, DOOMSDAY, is if nuclear facilities couldn't shut themselves off because they relied on grid power to do so and the grid was fried, or the safety systems got fried, or US nuclear or other countries nuclear weapons were activated by the pulse, or CDC safegaurds failed and samples were some how made active by terrorists or madmen. All in all sure people will die, but it won't be immediate, people die in accidents all the time. Overall the benefit to society will create a beneficial outcome as although it will be hard times for a bit it provides a chance to reassess industrial, social and technological planning as potentially there is room to break from the past and introduce newer more efficient systems that were not possible due to the ease of utilizing prior infrastructure.
Think of all the meat plants that won't be online, and even if they get online all the computer record systems of debit and credit will be hosed. People would need to write down who owes what, but we all know people are creatures of habit and would be adverse to change. Meat plants would grind to a halt, and how would they keep it all cold and transport it? All the shrink wrap stereofoam machines will be down. All the JIT (just in time) inventory systems would be trashed.
On the contrary I think that food plants will be ordered by executive order to operate and the absolutely needed electricity will be supplied by generators. The government won't just stop there are Continuity of Government plans in existence even in event of the destruction of congress and the president.
I wouldn't be suprised if people congregate to meat plants. Meat doesn't go bad immediately. You expect salt to be shipped there almost immediately for anything that can't be used, or for it to be preserved in fat from the animals which is an older way of preserving food. Making things like pemmican. There is natural preserveation process. What might be much more grissly is electric milking machines going bad since diary cows have to be milked, so I think you will have people enlisted to milk cows very quickly, but hey they'd probably get their fill of milk, of course pasturizers etc.. might be out of order meaning back to whole milk. Milk can also be turned into cheese etc.. Food safety monitoring may be reduced greatly though but standards are pretty high anyway, sure some people may get sick but few people die from bad food, and well its better than starving, it is food insecurity.
I never thought anyone would die of thirst in America, but that happen in New Orleans, all because people were too dumb to break rules and crappy protocols. Why on earth would anyone ever, ever turn away Wal-mart trucks full of free water when people are dying of thirst is beyond me. I would say, please dump it here, make an impromptu supply cache and we'll make sure it gets to the right people.
Yeah a lot of water insecurity can be solved by getting a good water filter. Water is a major problem but I would suspect pump stations would be a priority to repair and power.
How long can police and fire fighters maintain order? Sure some of their comms will be up but there will be mass confusion and civilians would have a hard time contacting them. Highways jammed full of knocked out cars would take ages to unclog. People were eating rotten food out of dumpsters two days after Hurricane Sandy in lower Manhattan. The supermarkets were dumping out trashed frozen dinners and meat, and the Manhattanites without refridgeration ate it with gusto. So many Manhattanites with a kitchen don't use it, they rely on take out food from restaurants. If it doesn't come from a box or can, and requires more than three steps they are screwed!
There is no doubt that every state effected will have the national gaurd called up, as well as potential some military but military will mostly be to suppliment DHS in gaurding federal buildings, or critical and strategic infrastructure. There might even be a draft, since the draft itself being invoked might be able to instill more general order and keep the unemployed, example drafting the unemployed, will remove people that will be effected and most likely to be zombies. Those that don't follow the draft will likely be scrutinized more heavily but the vast majority would be able to be targets for monitoring.
Now the US govt. can't pay for it but people without money work and a failure of social security will likely work for food anyway... and there will be a lot of work in getting important infrastructure back on line. People with money will definately bank out as the value will be dropping massively anyway.. they would invest very quickly their cash supplies. The market would also be massively swung, the fact electronic trading might be stopped would bring it to a halt, oh but it'd probably be shut down anyway.
Say all the Fortune 500 companies have everything EMP shielded, but what about all the mid-sized companies with no paper records or mom and pop shops? It might sound like a good thing to go back to the land, but lots of people invested years,and years of hard work in a company to make a comfortable living only to have it all taken away in and instant.
Yeah, I am moving away to a less densely populated area where I can be more self sufficient, but I am under no illusion should things get switched off most of my friends and family won't make it, or might get hurt.
Well I think there will be those who try to take advantage of it, but many of those people will get killed.. the ones who riot under martial law, or try to loot during massive duress without police being able to not have people killed during peace time will be the first to get shot. So the rioting threat may happen, but it should thin out.
There are a lot of what ifs but martial law will happen very quickly and continuity of government put into effect if required much like what happened in 911 but only way more activity.
I really like rural living. No complaints with that. The threat really can't be ignored especially for the critical infrastructure, you can't look in terms of cost when you have BP horizon level damage over and over again possible, the legislation needs to exist to force companies to be prepared for disasters if they represent a regional threat to environmental or public safety as a result of failure of their electricity or secondary resources that rely on electricity.