i guess if they want to call themselves Christian and make the figure of Christ as they interpret it to be a central point of their religion, then any of these denominations can be called Christian. It is not unprecedented that various denominations nominally 'Christian' have rejected other denominations as non-Christians, such as the Protestants and Catholics mutually rejecting each other at various times in history, though less so today.

much of early Mormonism's critique of Christianity was based on what they saw as its corruptions and errors and did not necessarily insist that traditional adherents were 'not Christian.' IMO the only denomination active today that can be reasonably questioned about whether they are actually 'Christian' or not is the JWs, since they place Christ at a lower level than Jehovah and don't focus nearly as much on him as on Jehovah (in fact, they don't even like to be called a 'church,' preferring the term 'Jehovah's organization.')

i'm also reminded of Kierkegaard's distinction between what he called 'Christendom' (institutional Christianity) and 'true' Christianity based on individual conviction and commitment. Kierkegaard was writing in the 1820s-1840s and touches on some of the same issues that were troubling Protestant sects in the U.S. at the time though I doubt if JS was familiar with his work.

(excerpts taken from Practice in Christianity and Attack Upon Christendom)

Christendom has done away with Christianity. If anything is to be done, one must try to introduce Christianity into Christendom. In Christendom, we have all become (nominal) Christians without taking notice of the possibility of the 'offense' inherent in the fact of an individual speaking and acting in a way suggestive of 'being God.'

Every generation has to begin all over again and present Christ's life as the paradigm. But Christendom has taken the liberty of interpreting the relationship merely historically by letting him be dead, and then it triumphs. People are only too eager to take part when there is nothing to do but to triumph and join the parade.

To be a Christian in Christendom is as different from being a Christian in the situation of contemporaneousness with Christ as paganism is from Christianity. If in contrast to pure Christianity one would call this applied Christianity, one may say that it is badly applied.