**For everyone scrolling along, this is intended to be a general explanation about the nature of Kritiks. yes, there will be some points that might not be true in every instance of every kind of criticism, but i think as a whole, i am offering a fair characterization.
At the core, this argument functions entirely differently than any other in that arguments like Counter Plans, Disadvantages, Plantexts, ALL operate on the Imaginative level of advocacy. For example, a traditional affirmative would read a plantext, and claim that if the policy were to hypothetically be executed, it would yield benefits (advantages) that are offensive reasons to vote Affirmative.
This offense, or reason to vote affirmative, assumes that the endpoint of the discussion should be to determine the desirability of the Affirmative's Plan by testing whether or not it is better than the status quo. However, seeing as the Plan exists in a hypothetical discussion (i.e. the world of fiat), the offense generated from the Plan's advantages only exist as long as what the judge/(we as debaters) care about is how good we can make this hypothetical world (whether it be with plantexts, counterplans, or the thesis of a Disad). But I'll get back to this.
The Kritik structurally calls into question some kind of ASSUMPTION or PRACTICE that the 1AC/Affirmative team/plan engages in. This can be anything from the assumption of participating in a free-market economic system (the Capitalism Kritik), to epistemological (where your knowledge comes from) assumptions behind Western politics towards others (Eurocentrism/Orientalism), to institutional racism prevalent in policy execution (Whiteness), to the Discursive (having to do with language) practices of describing conflict (Apocalyptic Representations).
Long story short, there are a LOT of kritiks written by lots of people that take shits on lots of kinds of philosophy/policy approaches. There are three primary parts to a basic critic, i'll use the Capitalism Kritik as an example:
This isn't the first part, but unlike a Disad (or even a Counterplan), there is no uniqueness. Whatever bad system of thought the Affirmative engages in is largely existent in the status quo (probably through the USFG doing a bunch of bad policies and being evil racist bastards who like to drone strike brown people to control oil, but i digress)--i realize the thought of a non-unique argument is troubling, but just go with it for now...
Link: pretty simple, this is the argument that the affirmative engages in a bad method of politics/debate OR that the Affirmative makes some bad assumption or ethical approach to a problem--for the Cap K, the story would be something like "The justification of the 1AC is rooted in market-based rationality which preserves the growth of Capitalism"
Impact: also relatively simple (based on the Kritik), this is the effect of the bad logic/ethic the 1AC engages in. The primary difference between Kritik impacts and Policy/Affirmative impacts is that while a 1AC might isolate a specific scenario for Economic Collapse (via American Competativeness) or war (via China-US conflict), a Kritik's impacts are structural and ongoing (meaning that they don't happen at exactly one time), however the impact of nuclear war or cycles of violence can be the endpoint of certain kritiks--With the Cap K, there are lots of impacts, but some common ones are structural violence from Poverty (starvation, disease, dehumanization, etc), environmental destruction (those free-market Oil companies sure to fuck the earth), or endless involvement in wars to secure resources.
The Alternative: This resolves the initial uniqueness problem i described earlier. While the 1AC's bad ethic or method may exist in the status quo, the advocacy of a different mode of thought or rejection of the 1AC's bad ethical approach is an action that seeks to resolve those harmful effects--back to the Cap K, a possible alternative might be to endorse a politics of anti-capitalism to resolve the harms of that social structure that the Affirmative operates under.
Now these are all relatively easy to understand on their own merit, but where a lot (and i mean a LOT) of people start to get confused and misunderstand the nature of the Kritik is the comparison of the Alternative advocacy (embrace politics of anti-capitalism) to the Plantext (the USfg should lift the Cuban embargo). Failure to understand the relationship between these two very different advocacies frequently leads people to questions like "Why does convincing 3 people in a room that Capitalism is bad matter when the Plan saves hundreds of lives?", "How does the USfg stop being capitalist?", or "How do you convince everyone in the world that Capitalism is bad just through this debate?" While these would generally be good questions, they all start from a fundamental misunderstanding of how the Alternative operates (being an action or mode of thought for the Judge to adopt) relates AND interacts with the Plan (a hypothetical USfg policy).
The Alternative of the Kritik and the Plantext of the 1AC are advocated in two different levels of advocacy. Kritiks are advocated in the material world where you and i make conscious decisions that affect the people around us, and educate ourselves about the world. The Plantext happens at the Hypothetical Llevel, a space of imaginative representation of the real world and hypothetical discussion via Fiat. For example, with Fiat, we could discuss how a High Speed Rail system might benefit people across the country, but that policy never happens. When the Neg defends an alternative (assuming that the judge is ethical), the judge then must vote for which team's advocacy is the most offensive (who has bigger/more serious impacts, who has the best internal links to the 1AC's impacts, etc).
However, as we discussed earlier, the 1AC's offense exists within an entirely separate space than the Kritik's. The Affirmative is only the best to vote for if we're speaking of a hypothetical situation, whereas the Negative then becomes the best in terms of what we leave the room with--this can be anything form knowledge of the content of the Kritik to how we orient ourselves towards the world, policy, and government that is effective. Sure, voting for the Negative won't make capitalism disappear, but if you think about it… voting for the Aff won't make the plan happen.
Now, while this seems somewhat pessimistic concerning the lack of apparent success of each team's political strategy, what this does is force us to ask an important question: what does each team's advocacy (plantext vs Alternative) inform us about and what do each of those teach us to do outside of this debate? This is important because debate, as an activity, teaches us how to do things like critically think about problems, analyze and understand certain literature, and have intelligent discussions where we are able to defend our arguments in hopes of persuading someone--all these skills beg the question about what do we use these for?
Ultimately, this changes the Role of the Ballot from determining the desirability of the Plantext as a policy option to determining which team's discussion/criticism/advocacy teaches us how to reorient ourselves, become educated about, and positively impact the world around us. Because the purpose of debate is to educate students (in some way), these debate come down to what we learn, and how we use that in a way that affects other people.
That is basically how a Kritik operates as a Debate argument. Many have Philosophical implications, some are very focused on policy execution. To get a better understanding of this Levers of Power argument about not being able to affect the USfg in the debate space and defaulting instead to individual activism/education, you should check out this article about Legal Normativity and Piere Schlag's arguments that was written by this law professor (i read the first two paragraphs):
Good Normativity Article: http://legalcommunic...ormativity.html