Conqueror's Haki is an incredible power that fans have rarely seen in One Piece. This is an ability only wielded by some of the very strongest, or those with the highest ambition. Conqueror Haki is a rare form of Haki found in only one in a million people. Even among these millions, only a few manage to awaken it.
Conqueror's Haki allows one to impose their willpower on others, scaring them or knocking them out. Its truest form increases both offensive and defensive powers of an individual. Fans clearly know that this is a significant power for anyone to use in battle. Within the Strawhat Pirates, Conqueror's Haki is not that common. However, certain members of the crew do have the potential to awaken it One Piece.
Note: this article will not include members who have already awakened Conqueror's Haki, which includes Luffy and Zoro.
Chopper
Chopper is the doctor of the Straw Hat Pirates and certainly a mighty fighter of the crew. Fans know he possesses majestic strength, thanks to his Devil Fruit and use of Rumble Balls. But, Chopper is not someone who will continue to use Conqueror's Haki ever.
In fact, the chance of him awakening this power is 0%, and no matter what happened in the story going forward, he will never gain this ability.
Frankie
The Shipbuilder of the Strawhat Pirates, Frankie is yet another individual whose chances of awakening Conqueror's Haki are quite low. There is absolutely no denying the fact that Franky is very powerful. But he can't even use the other two basic forms of Haki, and for him, getting Conqueror's Haki is really a long shot. Franky will certainly not go on to awaken this power at any point in the story.
Stream
Brook is a rather unique fighter in One Piece. Fans know that he holds the power of Yomi Yomi no Mi, and he channels the cold of the underworld with his sword, Soul Solid. Brook is very powerful and a trusted officer for a Yonko crew.
That said, for Brook, power-ups like Observation and Armament Haki make more sense than Conqueror's Haki. Like the others, Brook will most likely never enter awaken Conqueror's Haki.
Jinbe
Jinbe is a very skilled helmsman and fans also know that he has tremendous strength. Jinbe is an incredibly respected individual, known as the Knight of the Sea. Jinbe embodies both Otohime's and Fisher Tiger's hopes and dreams.
While there is absolutely no denying the fact that he possesses immense willpower, Conqueror's Haki is not that likely for him. That said, there's no denying the fact that Jinbe could potentially have this power and it wouldn't feel out of place at all.
Robin
The Archaeologist from the Straw Hat Pirates, Nico Robin is known to be a demon from the land of Ohara. She is the last known archaeologist from this land and someone of immense importance in the story, given that she can read Poneglyphs. Robin is one of the World Government's greatest enemies, and overall she's really a character that will excel with Haki.
It's puzzling that Robin doesn't have access to Armament and Observation Haki right now. In fact, for a character of her importance, even the Conqueror's Haki wouldn't feel out of place, given that she has great ambitions to find the Rio Poneglyph and make known the entire world's history.
Namie
Seeing Nami so high on the list may surprise many fans, but she certainly has a chance to awaken the Conqueror's Haki. First, Nami's true origin has not been revealed in the story and Oda seems to have planned something very emphatic around it, which may or may not be revealed later down the line.
After the events in Wano, Nami's anger manifested as a power similar to the Conqueror's Haki. This may be dismissed by fans as a gag, but it's entirely possible that Oda goes all the way with it and eventually proceeds to give her the Color of the Supreme King, even if it's only in its basic form.
Usopp
The chances of Usopp to awaken Conqueror's Haki are very high. Fans know that Usopp is an individual who lies often, but somehow his lies end up being true. Usopp has lied about having Conqueror's Haki on many occasions. In Wano he again repeated this life.
Most notably, Usopp would gain Conqueror's Haki befitting his character arc, where he goes from a cowardly individual to a brave warrior of the sea who embodies great ambition.
Sanji
The cook of the Strawhat Pirates and one of the strongest fighters under Luffy, Sanji has the best chance of getting Conqueror's Haki. Sanji is a prince of the Vinsmoke family, and fans know for a fact that the Vinsmokes were the Kings of the North Blue for a significant period of time. In the distant past, the Vinsmokes were insulted by someone in some way, and although the fans don't know much about it, it is known that they have Kingly blood in them.
Sanji with royal blood coursing through his veins certainly increases his chances greatly. On top of that, Sanji has the ambition to find All Blue, which is something even rarer than finding One Piece. This ambition, which burns strongly in his soul, along with the fact that he is a descendant of Kings, and is among the strongest in the series, only shows that Sanji will continue to awaken the Conqueror's Haki at some point in history. It would also complement Luffy and Zoro, and complete the Monster Trio, making them all Conqueror's Haki users.