the conception of politics as something wholly external from our character as humans is ridiculous
political belief is not like being a sports fan. the antipathy between my politics and the worst politics is not like the antipathy between giants and eagles fans, its not pure tribalism, its about entirely conflicting worldviews and value systems, and there is an element of one's character underneath those beliefs that is then filtered through the contexts of their experience and the world around them that creates a persons political beliefs. this is not a direct correlation where all the good people are leftists and all the bad people are rightists, no, there is a lot more to it than that. there are people with good hearts on the center right and some of the dirt worst pieces of shit in my neighborhood of the political spectrum, but i do believe that the polar opposite of my politics requires you to be either really ignorant or really malicious, and i would want a partner of mine to be intelligent and curious and have a beneficent and empathetic spirit
so, with this idea in mind, let us imagine my political opposite
i am wary of attaching myself to specific isms within the broader spectrum of leftism, but i am certainly in the realm of democratic/anarchist/syndicalist/libertarian leftism, and not leninism or maoism. i believe that it is a high crime that people are wealthy while others go without. i believe authoritarianism and totalitarianism to be inherently flawed and unworkable. I have a very strong belief in the inherent value of diversity and the need for social justice across a variety of axes. i'm a strong believer in secularism and religious pluralism but not anti-religiousness. i distrust patriotism for the sake of patriotism and define my loyalty to America as a loyalty to the welfare of all of its people, not the interest of its government and that governments benefactor. etc, etc, this is enough for the thought exercise
my political opposite would have very strong authoritarian and even a totalitarian bent. they would believe strongly in the supremacy of their own race and believe all others should be subjugated or eliminated. they would believe that there are two genders, and that each of the two has inherent roles, and deviance from those roles would be an evil. they would believe that homosexuality and transgenderism are abhorrent. they would blame the poor for their own lot in life and believe that those who die from poverty deserved it. they would believe in a single religion (which could be atheism) having supremacy over all others. they would demand blind patriotism from all citizens. this certainly sounds like a dystopian nazi caricature but the beliefs are common amongst the MAGA crowd that is currently running the nation, even if I have illustrated them in sharp relief here.
this is either a person who doesn't think for themselves at all or is pure evil, or some combination of both. there are beliefs this person has that are unconscionable and require malice or (in this time of information everywhere) an an almost impossible ignorance to sustain. the only way they're not a bad person is if they have very little capacity for critical thinking and thus buy into whatever they're told. So of the two possibilities: a bad person with hate and coldness at the center of their being or a person who does not think for themselves, neither person is somebody I have interest in as a romantic partner. maybe you can have some weird loathing kind of sex with them but thats not something im particularly into.
in short, being a leftist like myself is not a precondition to being my partner, but having a few key fundamental virtues and beliefs and having the ability to be "on my level" on a critical thinking basis (so that we can have engaging discussions about things because this is important to me) are preconditions, and there are a few sections of the political spectrum that preclude a person having either of these things (fascism, Objectivism, for two examples), or at the very least it shows that they have some maturing to do, as plenty of people have 'phases' of bad politics that they reform out of.
tldr: NO FUCKING WAY