But did it have to be like this? There are many ways Japan could have turned Midway into just another in a string of victories over the Americans. The Japanese carriers could have found the Americans first, they could have had more fighters aboard to beat off the American attacks. The list goes on and on. The US as well could have done things differently, or been far less lucky. They might not have broken Japans codes, could have been caught in a storm. Yorktown, already damaged could well have suffered some catastrophe. The list goes on and on.
How it happened is not important however (lets say Japans codes were not broken and the Yorktown was unfit to see action leading to the smaller carrier Wasp being substituted for her) but what is important however is that somehow Japan pulls a victory out of Midway. Sinking all three American carriers and a fair portion of their surface escort. Say two cruisers and a quartet of destroyers. Japanese losses meanwhile are very light. Say zero carriers or cruisers lost and a pair of destroyers being the only casualties on the Imperial side. This leaves the USN with only one real carrier in the Pacific and shattered morale. Japan meanwhile is buoyed by their success however and prepares for further operations against the USA.
What next for Japan? Well for starters it is very likely that a victorious IJN would intend to continue its ultimate plan of invading Hawaii, Fiji and Samoa. Fiji and Samoa would likely be quite easy targets. The British, which owned them, had not heavily defended the islands before the war. There was none of the airfields, fortifications or troops that Hawaii held. Plus both islands lacked the massive naval bases that Pearl Harbor did. The islands would probably fall easily to Japanese troops.
Hawaii was a totally different story however. Even before the Japanese attacks the island held extensive defenses. Following the attack however it could be said that Hawaii had become an american redoubt in the pacific. The island bristled with AA guns, Anti-ship guns, machine gun pillboxes and flame thrower pill boxes. The island was defended by a very capable series of airfields, each with at least a squadron of fighters. That was not mentioning the troops stationed in the island. Hawaii would be a very tough nut to crack.
But could they do it? Assuming that they could take out the garrison at Midway and establish a real blockade of the Hawaiian islands then yes. Probably they could over time take the islands. Afterall the islands already needed regular shipments of food to feed its population. If those shipments were suddenly stopped then perhaps the people would surrender to stop their suffering. Not that it would work but perhaps they could be convinced to...
Following the theoretical capture of Hawaii then Japan would move onto the second part of their war plans. That of negotiating with the United States for an end of the war. You see Japanese planners had never meant for a long war with the US. Rather they planned to quickly destroy the American fleet and take Hawaii. Unable to continue to fight it was hoped that America would give up and end the war. But would the USA have been willing to end the war after receiving such a brutal beating?
Following a loss at Midway the United States Navy would be left with just two carriers (The badly damaged Yorktown and the Saratoga) neither of these ships would be likely to be deployed on independent missions. Or even leave the dock for some months. Furthermore the Yorktown would likely still be at Pearl Harbor when the Japanese began their blockade. Thus bringing US carrier strength down to a single carrier. It would be most of a year before new carriers of the Essex class would arrive to turn the tide. By that time Japan would likely hold a total of at least eight carriers, probably more. It would still take some time before the US would be able to achieve parity with Japan, let alone superiority.
Furthermore by this time the morale of the American troops stationed in the Pacific would be very low. Japan would be viewed as nearly invincible, unbeatable and dominant. Any troops stationed in Hawaii, with no possibility of support or relief, would likely lead to a very dispirited and halfhearted defense of the islands.
But would even the loss of Hawaii lead to the US considering any peace proposals? That is not something that is so easy to anticipate. Afterall Americans are stubborn people that often choose to ignore facts staring them in the face. Thus it is possible that the US might stay in the war and wait until new carriers were launched to defeat the IJN. If this was the case then the Japanese would loose. They could not destroy every American carrier with no losses. And it would be far easier for the US to replace losses than for Japan. Even though the US would likely win the war would likely drag on until at least 1946, probably 47. The Japanese would have ample time to fortify and defend their island possessions. Thus racking up American casualties as they attempted to take back the islands.
That is to say nothing of the death toll in China with a Japan defeated in 46 or 47. Even in our time line Japan still killed nearly four million, even more would likely die by the time the US won. And who knows who would emerge victorious from the raging Chinese civil war?