When conservative commentators say the “Golden Age” of marriage they are usually referring to the 1950s model.
refer to, not say. Additionally, I think a comma is preferred after the word "marriage". I would follow up this sentence with the definition of the 1950s model. The topic is unclear otherwise.

That decade represents an era that is already gone for many Americans where life was balanced, simple, and innocent.
This sentence is just terrible. The rest are okay, but this one doesn't make sense at all. First of all, if you're going to start off with "That decade", then you should say "the model of the 1950s" in the previous sentence, because otherwise you aren't really mentioning a decade in the previous sentence - you're using it as an adjective rather than as the object of a preposition (where the prepositional clause is adjectival, true, but the distinction is critical to the next sentence). Take out "that is already gone for many Americans". It confuses the reader because when you say "where" the reader is tempted to refer back immediately to "Americans". Additionally, it's a ridiculous and incorrect statement. The 1950s are gone for all Americans unless Marty McFly really has a time machine. Also, you're not talking about a place, but a time, so use "when" instead of "where".

A time in American history where a high school education promised a comfortable living and where family values were presented to audiences through television shows like "Father knows Best" an "Ozzie and Harriet."
This is a sentence fragment. You can start with "The 1950s represent a time..." without worrying about repetition if it's done to rhetorical effect.

When they evoke the “good old days” it’s the 1950s model they have in mind; a father with a good job, a mother who stays at home and raises the children, and a house in the suburbs with a white picket fence.
The "they" must refer to conservatives, but the intervening sentences don't make that clear. Repeat the word or use a thesaurus to find a word with similar meaning. However, you've already said the first part of the sentence in your opening sentence, and it doesn't seem to be serving any function repeated here. I would take out "it's the 1950s model they have in mind;" (and, for the record, avoid contractions in formal compositions) and replace it with "they assume".

It’s easy to see the draw of the 1950’s marriage; solid and stable marriages seemingly without the more modern problems of divorce, infidelity, spousal abuse, and discontent.
This sentence is somewhat clumsy. I would ditch the semicolon and start a new sentence with a lead-in like "It presented an idealized fantasy of...".

On the surface, everything seemed fine. However unhappiness often lurked beneath the surface, especially on the wives’ side.
Yes, we've all watched Mad Men, haven't we? Put a comma after "However" and you can leave this from a stylistic standpoint, though I don't like the phrase "wives' side" - I assume you mean "of the marriage", but it's still a bit unwieldy.

Ultimately, you should try to draw some conclusions of your own rather than state truisms. Was the "1950s model" of marriage really that idealized? On television shows, it certainly was. However, what about other media? There are plenty of movies that came out during the period that showed a more mature and nuanced view of the world, and plenty of shocking books directly challenged the post-war "American Dream". Think about this: The Catcher in the Rye, Lolita, Peyton Place and On the Road were all published in the 1950s. In cinema, you won't find idealized marriages in Sunset Boulevard, Vertigo or The Man in the Gray Flannel Suit. Isn't it possible that television just presented a simplistic idealized form of life that the dull-witted masses could understand? Didn't television still do that in the 1980s, over twenty years later?