If Mahabharata has two characters who have received the most humiliation, one is Draupadi and the other is Karna.
Draupadi has longed for a husband who will have wisdom and moral values, will be strong and well built, a good archer, handsome and intelligent.
Karna is the only character in Mahabharata who has all these qualities. The gods knew Draupadi’s wish well ahead of time and gave all these qualities to one man. Karna.
Also, all these qualities have been equally divided in Pandavas (Yudhistira for moral values, Bhima for physical strength, Arjuna for archery, Nakula is handsome and Sahadev is the most intelligent).
But Alas, for time had other plans
Dronacharya knew that Karna is far superior than Arjuna, hence he denies to teach him archery lessons. Bhisma knew that Karna is a big threat to Arjuna and thus prevents him from entering the war during initial days.
Its fate or destiny which parted Draupadi and Karna. He would have been a better ‘only’ husband for her than the five she got as he was as good as any of the pandavas when it came to virtues and valour.
But from the political and “Dharma’s” point of view, she has to be married with Pandavas. Thats the plan. Karna negates Arjuna, which creates a balance.
Draupadi herself prevented Karna from participating in the Swyamvar, calling him a Suta Putra. This insult by Draupadi was one of the reasons for her downfall in the court room where she was disrobed in public, leading to humiliation of Pandavas, reaping the seeds of war.
Many years later, she learned from Krishna that Karna is not a suta putra but the eldest son of Kunti.
To this, Draupadi regrets saying,
If I had married him, I would not have been gambled away, publicly humiliated and called a whore. For he has all the qualities possessed by my 5 husbands.
Draupadi has always favored Arjuna but alas, Arjuna was not happy with the fact that he has to share the prize he has won with 4 brothers. Arjuna, on the other hand, favored Subhadra. Draupadi knew this too, which is why she starts having a soft corner for the next best archer, Karna.