"You're for liberty or you're for slavery" has been called a "false dichotomy".
A quick search finds a definition for a false dichotomy:
A false dilemma (sometimes also referred to as a false dichotomy) is a logical fallacy, which occurs when a limited number of options are incorrectly presented as being mutually exclusive to one another or as being the only options that exist, in a situation where that isn’t the case. For example, a false dilemma occurs in a situation where someone says that we must choose between options A or B, without mentioning that option C also exists.
Those that claim liberty or slavery is a false dichotomy fail to present an option C to support their claim.
One is either for slavery or against slavery. To be scholarly on this issue, I will acknowledge one can be neither for nor against something at any given time. However, such a third position is totally without any merit. To sharpen the focus and prove my claim, what changes if you or another are being enslaved?
Without empathy, you can be indifferent to another's plight. On the other hand, you wouldn't be indifferent to your own enslavement.
You should understand that if something can be done to another, that same thing can be done to you. The logical result should be that if you don't want to be enslaved, you must defend others when they are targeted for enslavement.
Liberty or slavery is an issue of what is moral. Logic dictates that a person neither for nor against slavery has no moral compass. I suspect and submit that humans missing moral compasses are humans capable of doing great evil and great harm to other humans, to include enslaving or killing among other actions.
If you are not 100% free of your owner's demands on your life, liberty, or property, then you are a slave. This is an all or nothing dichotomy. If you feel you must, amuse me by attempting to logically refute enslavement.
Now on to the other choice: Liberty.
The author is almost 200 years dead. I have found few have awareness of the author's words; "Rightful liberty is unobstructed action according to our will within limits drawn around us by the equal rights of others. I do not add 'within the limits of the law' because law is often but the tyrant's will, and always so when it violates the rights of the individual."
If you are not free to do anything that does not harm another, then you are not at liberty. Malum prohibitum (plural mala prohibita, literal translation: "wrong [as or because] prohibited") is a Latin phrase used in law to refer to conduct that constitutes an unlawful act only by virtue of statute, as opposed to conduct that is evil in and of itself, or malum in se.
Mala prohibita are rules the owners give to the owners' slaves.
Since being a slave is absolutely antithetical to being at liberty, the claim that "You're for liberty or you're for slavery" is NOT a false dichotomy.