Basic question is the thread title.
Clarification: Except for the distribution of the “Eskimo” languages, those spoken aboriginally (i.e., at the time of historical contact) in the Americas are members of distinct families and stocks from those spoken in the Old World. Except for a few nutbars and the theoreticians trying to find the common ancestral language if any, nobody sees a relationship between, say, German and Navajo. Many of these languages have been driven to or near extinction by the spread of English, Spanish, Portuguese, and French throughout the Americas.
I apologize for the use of “viable”, but I do mean it in its strict metaphorical sense: the ones that can reasonably be expected to survive as the spoken medium for a significant culture group of more than a few thousand. To parallel this in quasi-familiar Old World languages, Telegu, Swahili, German, Korean, each the native language or lingua franca of millions, have reasonable expectations of long-term survival. Absent preservation efforts or highly improbable coincidences, Frisian, Liv, and Scots Gaelic do not. They may be preserved as matters of interest, “spoken” by preservationist enthusiasts in an effort to “keep the language alive,” but are unlikely to be the common medium of verbal communication of any significant culture group.
Okay, given that background, which “American Indian” languages (North and South America) are likely to survive as living tongues? And are there any other valid candidates (things like Afrikaans that have evolved a separate existence since the Age of Exploration) in the New World?
While this is an opinion question, it strikes me as GQ rather than IMHO, as having “expert opinion” valid answers?
As a secondary question, what groups do they belong to? I know I can get that answer from Ethnologue, but I’d rather not slog through San Podunquito Apache (total speakers: 6) and the like to get the answer.