Miguel's story over the entire course of his life is told. The one constant over most of it is the push and pull between various factions leading to he never feeling like he fit in: his American life versus his Puerto Rican roots; his want for that better, more financially secure life versus his working class growing up both in Pennsylvania as well as Puerto Rico; he wanting that loving family yet being divorced and being estranged from his children, most specifically Andy; and his relationship with Rebecca which did not sit well with the Big Three, especially Kevin who saw it as a betrayal to their father, Miguel's purported best friend. In the era of Kate's second marriage, Miguel has become the de factor center of the "Pearson" family in being Rebecca's primary caregiver, and thus being the intermediary between Rebecca and the Big Three in relation to her care. But in carrying the weight of the Pearson family on his shoulders, he is also no longer a young man who is facing health issues of his own, making that weight heavier and heavier despite putting on that brave face in his vow to Rebecca and thus himself to be there for her.
—Huggo