In New England, each town reports its election results separately. There's no central tabulation of the vote like in other states until the official results are released. The AP has to call each town's elections officials to get the numbers, and they probably haven't bothered to do so with half the tiny towns in the state (or they're not answering because there's one person in the office who works part-time).
How efficient and progressive!
Meanwhile in Louisiana and Mississippi, all of the votes have been counted.
Given the general lack of protection against fraud in the US, the New England way is, in fact, reasonably efficient and quite progressive. The only reason the US elections function at all is that things are very decentralized: this, essencially, tends to ensure that incentives to cheat are smallish and that whatevve cheating there is roughly proportional to actual vote. The more decentralized the vote administration and counting is, the more likely it will stay that way.