I was once told that whenever I see the word "politics", I should replace it in my head with the word "power." That exercise has been a really helpful way for me to conceptualise what it means when we talk about the political compass of a show. How does the series negotiate the distribution of power over various characters? Who has it? Who doesn't? Who wants it? Who will never get it? Who -- and this is the biggie -- deserves it? [And I suppose I use this 'power' definition for non-fandom discussions as well. So, for example, when people say they're "not into politics", I generally take it to mean that they're not interested in unpacking their own power and privilege, and that they're even less interested in enfranchising those who have none.]
Third Season Doctor Who engages a lot with that last question (Who deserves power?), most prominently in the final arc, with the Master as foil for the Doctor, but what really gives the story texture is the reality that Martha Jones (and thusly, people like Martha Jones) never had a penny in that race. As much as she is an empowered character, she never actually holds power. Her most daring, brave, badass act is to make people believe in the Doctor. What if, instead, everyone had thought "Martha" at that final moment at the end of the countdown (FINAL COUNTDOWN!!!!!!)? The mythic resurrection that took place could've just as easily worked to bestow her with superhuman abilities. If the Massive Psychic Network could turn Golem back into David Tennant, it certainly could've turned Martha into Something Capable of Defeating the Master.
(And I don't know if the term "master" has political resonance outside of the Americas & Caribbean, but...even without that particular tragic history, the antithesis of Master is Slave. Can we talk about the way Martha's mum and sister are made to dress in little maid outfits whilst serving the Master toward the end? I refuse to believe that was anything other than 100% purposeful, especially because we've seen someone dressed in a maid's uniform before, and it was Martha, when she was the Doctor's servant, so.)
Davies is incredibly aware of the show's racial politics (or less generously, he is aware that race exists, and that writing it out of existence helps no one, especially not those who are marginalised.) That's not to say he always does it well or plays it right or strikes the correct note, but with me, any attempt to honestly engage with these issues of racialised power dynamics wins my favour.
"Human Nature" (by far my favourite episode of the series) problematises the relationship between the Doctor and Martha Jones in a way that's tangible for those who might have otherwise missed the racial dynamics apparent in the Doctor/Martha arc. Quick recap: The Doctor is running from Evil Scarecrow Aliens Who Eat Time Lords, and in order to hide, he transforms himself into a human and hides in Pre-War England, not remembering that he is the Doctor. Martha knows all and works as his servant.
He is kind and benevolent, as nice as any master could be, but what's missing is any awareness of Martha's inherent human dignity. The truth is, the doctor could never love her, because he does not see her as something worthy of love (or maybe he does, but he's so sold on White Supremacy that he won't allow himself to acknowledge his feelings for her). Martha says it best, that even when the Doctor does fall in love with a human, it's not her. It will never be her, and it can never be her. No, it's the white, blonde nurse who puts Martha down on the regular.
And to some extent, the show recognises this as fucked up. Consider the Shakespeare episode. Even though his desire is fetishising, William clearly and vocally finds Martha extremely attractive, and is like, YO DOCTOR, WHEN YOU GON TAP THAT? And no, desire/attraction does not equal love, but what does it say that the Doctor won't even consider that possibility, that Martha is beautiful and good worthy? Maybe it's that he's not over Rose, but then why does he fall so easily and randomly for the White Chick in "Human Nature", and still think so little of Martha?
And JACK. (Oh, I totally squeeeeeeed when we find out he's the Face of Boe). But yeah, doesn't Monsieur Harkness sum it up nicely? That the Doctor doesn't care about anyone -- unless they're blonde (referencing Rose...but it also harks back to Human Nature chick), and Martha is like, OH ROSE WAS BLONDE? OF COURSE. FUCKING OF COURSE. And I think that's the unfolding of her realisation. That scene is meant to be somewhat tongue-and-cheek, I think, but the writing isn't oblivious to the ways social categories influence and shape attraction and love, and that's a strength of the narrative.
So then, where does that leave Martha? She can't effectively obtain power (being that it's a White Man's Time Lord's World). And she will never be the Top Pick, the First Choice. (My Precious Baby. Doesn't she know she is number one forever and ever in my heart? Seriously. I cannot even remotely access the reality that people throw hate at her...or anything other than IMMENSE DEVOTION AND LOVE. She is literally perfect.). But anyway, she understands at the end, the Doctor aint shit noway. She bought into the Whiteness Hype (as so much of us do as younglings), something Martha's mother worried Martha was doing from the outset. Who is this Doctor that showed up in your life, that has you so entranced, even though you barely know him? Even though he hasn't done shit for you?
But Martha's arc is that she realises in the end, "I am good," regardless of the Doctor's validation or approval. "I have better things to do than hop around the universe with the Embodiment of White Supremacy. I have lives to save, damn it. I am a doctor, and not a fake doctor who has no apparent skills other than general tomfoolery, a real doctor with medical training."
ETA: I finally remembered why I was so biased against Moffat! He wrote Sherlock, and I despise that show with the fury of a thousand (sentient, alive) suns. Benedict Cuntsnatch aint shit. Martin Freeman aint shit. Moffat aint shit. Soooo, we'll see if I continued. Part of what i enjoyed about this season so much was the racial narrative, and Moffat is literally the worst at race ever. The Worst.