This is really two questions. First, did Athenian participants oppress people who were not eligible participants in the democracy? That one is easy. There is no question that they did. Women had no legal capacity and were kept in the house, locked away in the women's quarters. Metics (resident foreigners) were excluded from citizenship no matter how many generations they lived in the city. And slaves may well have been an absolute majority of the population.
The more difficult question is whether oppressing non-eligibles was a political movement. In other words, was there controversy over how to treat non-eligibles? And, if so, did the democratic public favor treating them worse than the democracy's aristocratic critics? Note that this can take at least three forms. There can be a movement to improve the lot of non-eligibles, and opposition to it. There can be a movement to worsen the lot of non-eligibles and opposition to it. Or the position of non-eligibles can be uncontroversial in the democratic body politic, but certain aristocratic critics can tut-tut over how unenlightened the common people are. Let us consider, then, how Athens treated the three groups of inhabitants who were not eligible participants.
Women. Undoubtedly Athens treated its women abominably. Women were kept locked up in the women's quarters, leaving the house only for festivals or funerals, and told that the ideal woman was she who was least on the tongues of men, for good or ill. Furthermore, it would appear that the high point for democracy was a low point in the treatment of women. Women in Homeric times are not portrayed as veiled and secluded; women's position rose again in Hellenistic times (i.e., the Greek empires created by Alexander the Great). It is hard to tell how much of this was coincidence and how much was related.
Certainly it is no secret that in highly hierarchical societies, women as wives and mothers of rulers can exercise political power in ways not available to women in more egalitarian societies. This applies to Greece no less than other societies. For instance Herodotus recounts that in the Greek colonies under Persian control, Artemisia of Halicarnassus succeeded her husband to rule as queen because their son was under age. She accompanied Xerxes on his expedition and was Xerxes' best adviser, the only one to warn him not to engage the Greeks in a sea battle. When Xerxes, despite suspecting that she was right, proceeded with the attack, Artemisia fought in the Battle of Salamis and commanded five of the best ships. Afterward, she advised Xerxes to get out while the going was good, and this time he listened. Likewise, in oligarchic Sparta, women were not secluded, but traveled about freely, engaged in athletic training, lorded over the helots, and ran the household, and sometimes the community, in the men's absence. In egalitarian Athens, women were shut out from political power altogether.
Women need not have access to political power to excel in other ways. In the late seventh and early sixth century, B.C., on the Island of Lesbos, Sappho became a poet so great that men did not rebuke her for her unwomanly behavior, but looked upon her poetry with unqualified admiration. She was classified as one of the nine great lyric poets all educated young men should read (the other eight, of course, were all men) and hailed as the tenth muse. Solon, himself a poet, was said to have said after learning one of her poems that now he could die happy. Classical Athens was the scene of a great flourishing of culture, art, and intellect, but that flourishing appears to have been an all-male affair. Not one women is named as a writer, poet, artist or philosopher.
Well, the opportunities of women of the elite tell us little about the lives of ordinary women. In Egypt, women had legal capacity and could own property, contract and sue. In Athens, women had no legal capacity and were entirely under the guardianship of their nearest male relative. Roman women lacked legal capacity, but were not kept secluded, but could come and go as they pleased and served as hostess along with their husbands. Finally, I note that the columnist Georgie Anne Geyer has remarked (won't bother looking for link) that advancements in the position of women always take place under at least somewhat repressive regimes because under a democracy men are invariable able to block any improvements for women. Kicking down is popular.
In short, Athens clearly treated half its population badly. I see no evidence, however, that this was a political movement. It appears to have been completely uncontroversial and challenged by no one, including the women themselves. Certainly so far as I am aware, there was no political movement afoot either to give women greater rights or to reduce them. Nor do the democracy's critics seem to have tut-tutted much over how it treated its women. Critics often derided the Assembly as a bunch of rowdy rabble. But, despite the proverbial violence of lower class men toward their wives, I am not aware of anyone speaking of them as the sort of riff-raff who beat their wives or made similar comments. Plato, it is true, proposed in The Republic to give women complete equality. But there are little clues here and there that he didn't really mean it. Aristotle, commenting on Sparta, listed the greater liberty it offered to women as one of its defects. And Plutarch in his Life of Lycurgus defended Spartan women against charges that they were immodest or promiscuous. Yet in his ultimate assessment, he said:
And so their women, it is said, were bold and masculine, overbearing to their husbands in the first place, absolute mistresses in their houses, giving their opinions about public matters freely, and speaking openly even on the most important subjects. But the matrons, under the government of Numa, still indeed received from their husbands all that high respect and honour which had been paid them under Romulus as a sort of atonement for the violence done to them; nevertheless, great modesty was enjoined upon them; all busy intermeddling forbidden, sobriety insisted on, and silence made habitual. Wine they were not to touch at all, nor to speak, except in their husband's company, even on the most ordinary subjects. So that once when a woman had the confidence to plead her own cause in a court of judicature, the senate, it is said, sent to inquire of the oracle what the prodigy did portend; and, indeed, their general good behaviour and submissiveness is justly proved by the record of those that were otherwise. . . . . Their respective regulations for marrying the young women are in accordance with those for their education. Lycurgus made them brides when they were of full age and inclination for it. Intercourse, where nature was thus consulted, would produce, he thought, love and tenderness, instead of the dislike and fear attending an unnatural compulsion; and their bodies, also, would be better able to bear the trials of breeding and of bearing children, in his judgment the one end of marriage.Such was the view of women by democracy's aristocratic critics.
The Romans, on the other hand, gave their daughters in marriage as early as twelve years old, or even under; thus the thought their bodies alike and minds would be delivered to the future husband pure and undefiled. The way of Lycurgus seems the more natural with a view to the birth of children; the other, looking to a life to be spent together, is more moral.