Our Gedolim have told us to go to the rally in Washington during this critical moment of Din of Klal Yisrael.
My children asked me, What is the purpose of going to the Rally? Do we think that the nations will really care? For whom are we doing this?
I had the merit of speaking with someone today who said she felt that we needed to scream as a Tzeaka to Hashem. We need a world of Mashiach now. How can we go on for even one more moment while we have over 200 hostages in the hands of our enemies, and seeing a world of death, and sheker (lies). How can we continue to accept this type of world as a reality? We must Scream, just as Hashem redeemed us from Mitzrayim with our screams as it says:
By S’dom we see that Hashem also responded to a scream (Tzaaka) of a girl treated cruelly and other acts of cruelty leading to His judgment to destroy S’dom. As it says: אֵֽרֲדָה־נָּ֣א וְאֶרְאֶ֔ה הַכְּצַעֲקָתָ֛הּ הַבָּ֥אָה אֵלַ֖י עָשׂ֣וּ ׀ כָּלָ֑ה וְאִם־לֹ֖א אֵדָֽעָה, I will go down to see whether they have acted altogether according to the outcry that has reached Me; if not, I will take note.
“The Torah had in mind a special outcry, namely the one by the soul of the girl they had murdered in such a cruel manner (Bereshit Rabbah 49,6). Later on the angels say Hashem destroyed the evil S’dom because the screaming was so great.
because the outcry against them before Hashem has become so great that Hashem has sent us to destroy it.”
Interestingly , Mordechai employs the use of Zaakah in the time of Purim, and there are powerful parallels which I think we can use in our Kavanos when gathering together at the rally tomorrow biezras Hashem.
Until he came in front of the palace gate; for one could not enter the palace gate wearing sackcloth. 
The Alshich Hakadosh says that Mordechai screamed זְעָקָ֥ה גְדֹלָ֖ה וּמָרָֽה, to counter the voice of the bitter scream of Eisav to his father in this week’s parsha, not so coincidentally, I think. His intention was to weaken the voice of Eisav, when he screamed wailing to his father; and Mordechai screamed a זְעָקָ֥ה גְדֹלָ֖ה וּמָרָֽה to Hashem with that in mind.
When Esav heard his father’s words, he burst into wild and bitter sobbing, and said to his father, “Bless me too, Father!”
Rav Shlomo Halevi Alkebetz in Manot Halevi on this pasuk in Megillash Esther says that the scream was not for the king, or the nation, rather it was a Tefillah to Hashem. Mordechai wanted to gather large crowds and the nation together in tefillah as I understand it in this form.
May we be zoche to use this rally just as Mordechai Hatzadik did; when he gathered all the nation together as a voice of Tefillah of ZAAKA to Hashem, to once and for all weaken the power of Eisav, our enemies, and move our world into a world of Hashem Echad revealed NOW..