In David Sedaris's "A Modest Proposal," how does the character face exclusion from his society and then push against the boundaries imposed by society?

"A Modest Proposal" is a nonfiction essay, not a short story, so the author is presumably writing about himself and cannot strictly be called a character. Written in the first person, the author discusses his reaction to the Supreme Court decision to affirm the lifting of a ban against marriage between two people of the same gender. Sedaris is gay, and he often writes about gender and sexuality issues. He has lived with his partner, Hugh, who he often writes about in his essays, for more than two decades. The boundaries he discusses in the essay are societal attitudes toward gay people and toward marriage.
For a number of reasons, the couple has lived in Europe for most of their time together; he has also written about their lives in France and, more recently, in England. In France, civil partnership has been legal since the 1990s, and in England, prohibition against marriage between people of the same gender was lifted more than two years earlier than in the United States.
Marriage, or being legally prevented from entering into this type of partnership, was not one of the reasons they left the United States. Until the Supreme Court decision, Sedaris claims, marriage had not been near the front of his consciousness. Nevertheless, the public endorsement of this civil rights breakthrough made a strong impression; he was so excited to learn what the court’s decision would be that he took his iPad out while he was walking around so he would not miss the announcement. It got him thinking about what the meaning of marriage compared to other manifestations of commitment.
Thinking of changes in such attitudes also prompted reflections about being gay as a youth in North Carolina, when “queer” was used as an insult—even by his mother—and many people thought that being gay could be “cured” through psychiatry. After he came out to a close friend, however, the need he had felt to deny his identity and the fantasies of “outgrowing” that aspect of his identity faded away.
Reflecting on marriage included, for Sedaris, his overall negative attitude toward weddings, of which he had sat through many; weddings were something gay people did not need to inflict on their family and friends. With this type of overall attitude, he was surprised to find how moved he was when the Supreme Court ruling came down and was published in the London paper.

I read it, and, probably like every American gay person, I was overcome with emotion.

Emotion aside, Sedaris presented the idea of marriage to Hugh as a financial matter, into which he refused to enter. Irritated, Sedaris insisted.
After an estimated 18 proposals over two weeks, once Hugh agreed, “reality set in.” He thought about having a “husband” and having other people speak of Hugh that way—even that the word would be used in his obituary. So he let the marriage question slide, and considers the two of them are “engaged, I suppose, [with] our whole lives ahead of us.”
https://www.newyorker.com/magazine/2015/09/28/a-modest-proposal