The midrash explains that the Emperor Caligula had instructed that idols be placed in the Temple. The high priest Simeon the Mild told the people not to worry because God would perform a miracle and prevent this from happening. At that moment, they heard a voice from the temple saying that Caligula has been killed and the decree is nullified.
They midrash then tells about Caligula's soldiers traveling to Jerusalem with the idols. One (unnamed) Jewish leader instructs the people to meet the soldiers and try to stop them. The Jewish "notables" went out and told Caligula's emissary that they are ready to die to prevent the idols from being placed in the Temple. The notables kept "crying aloud and beseeching" the emissary, who apparently got quite annoyed, and asked why they didn't pray to their God in heaven rather than bugging him. As he went from city to city, people coming from the city to meet him. But when he went into the cities, he saw people in sackcloth and ashes in the marketplace. The then learned that Caligula had been killed and his decree nullified. The Jews dragged the idols through the streets.
The Jews employed two tactics to deal with this problem. The first was to ask God for a miracle. This was the approach of Simon the Mild as well as the Jews who put on sackcloth and ashes. The second was to confront the Roman emissary directly, as the notables and the people coming from the town were doing.
There is a nice parallel between this midrash and the Book of Esther. There, once the Jews learn of the kings decree, they took the same approach as the city people in our midrash: they put on ashes and sackcloth and wail.
And Mordecai knew all that had transpired, and Mordecai rent his clothes and put on sackcloth and ashes, and he went out into the midst of the city and cried [with] a loud and bitter cry. . . . And in every province, wherever the king's orders and his edict reached, there was great mourning for the Jews, and fasting and weeping and lamenting; sackcloth and ashes were put on the most prominent.
The problem is that this strategy did not look like it would work. So Mordecai convinced a somewhat reluctant Esther that she needed to intervene. And she does, and that saves the day.
One of my teachers, R. Edward Feinstein, has explained Esther as an argument against the ashes-and-sackcloth approach and in favor of direct action and power. Mordecai's wailing does not work; only Esther's direct and very human intervention with the king works. But I think the relationship may be more complicated that that. After all, it was Mordecai's embarrassing behavior that caused Esther to get involved. (See Esther 4:4-17.)
The tension between these two approaches has continued through Jewish history. The Jews in our midrash may have avoided idols being placed in the Temple, but 25 years later Romans destroyed the Temple itself. The unsuccessful Bar Kochba revolt 65 years after that was the result of both poor political and religious thinking. The perceived Jewish passivity in response to pogroms and the Holocaust, the direct secular power approach of the early Zionists, the power of the modern Israeli military, and the current dispute over the Orthodox serving the Israeli military all center around the tension between how we respond to external threats: introspection, prayer, ashes-and-sackcloth on the one hand, or direct political or military power on the other. I cannot solve these problem (and am not even going to try), but I simply note that our midrash nicely captures the tension between these two approaches.