the connection between "kotzer ruach" and avodah zarah

The problem with the kal v'chomer (6:12) of הֵ֤ן בְּנֵֽי־יִשְׂרָאֵל֙ לֹֽא־שָׁמְע֣וּ אֵלַ֔י וְאֵיךְ֙ יִשְׁמָעֵ֣נִי פַרְעֹ֔ה וַאֲנִ֖י עֲרַ֥ל שְׂפָתָֽיִם is that just four pesukim earlier the parsha tells us that Bnei Yisrael did not listen to Moshe because  וְלֹ֤א שָֽׁמְעוּ֙ אֶל־מֹשֶׁ֔ה מִקֹּ֣צֶר ר֔וּחַ וּמֵעֲבֹדָ֖ה קָשָֽׁה, they were overburdened with hard work.  Pharoah did not face the same challenge of being overworked; he could carve out time to listen csrefully.  Why was Moshe convinced that just because Bn"Y did not listen, Pharoah would not listen either?

Ramban contrasts the reception Moshe got from the people this time around with their reaction to his words in last week's parsha.  There, the Torah tells us that (4:31) וַֽיַּאֲמֵ֖ן הָעָ֑ם, they believed the message.  Here, they seem deaf to what he has to say.

Ramban argues (see Rashbam who disagrees) that we should not conclude that the people no longer believed in Moshe or his message.  He writes:

לא בעבור שלא יאמינו בי״י ובנביאו, רק שלא הטו אוזן לדבריו מקוצר רוח, כאדם שתקצר נפשו בעמלו, ולא ירצה לחיות רגע בצערו, מדעתו שירוח לו אחרי כן.

The people did believe.  However, the promise of the 4 leshonos of geulah, the promise of a future in Eretz Yisrael, seemed a distant dream that had no bearing on the harsh reality of their day to day burden of work and the oppression they labored under.  

This also seems to be the view of Rashi, who explains ולא שמעו אל משה – לא קיבלו תנחומין.  The people did not doubt the truth of Moshe's words; however, the message provided little consolation to them in their present situation.  

The Midrash Rabbah, however, writes that וְלֹא שָׁמְעוּ אֶל משֶׁה וגו׳ – הָיָה קָשֶׁה בְּעֵינֵיהֶם לִפְרשׁ מֵעֲבוֹדַת כּוֹכָבִים.  The people rejected Moshe's words because they remained attached to their belief in idolatry.

The Midrash seems to be not only at odds with Ramban/Rashi, but at odds with the words of the pasuk itself.  The pasuk tells us that it was  מִקֹּ֣צֶר ר֔וּחַ וּמֵעֲבֹדָ֖ה קָשָֽׁה, because of the burden of work that the people did not listen.  Why does the Midrash attribute their not listening to avodah zarah?

My wife's grandfather, R' Dov Yehudah Shochet, quoted from the Baal haTanya that avodah zarah does not simply mean prostrating onself to an idol.  Avodah zarah means having an identity, a will, apart from G-d's.  When all that exists for a person is G-d's will, then no matter how difficult the task, no matter what burdens and obstacles there are, a person will make an effort to get the job done.  When all that exists is ratzon Hashem, then קֹּ֣צֶר ר֔וּחַ and עֲבדָ֖ה קָשָֽׁה  don't get in the way. 

There is no contradiction between the plain meaning of the pasuk and the Midrash's interpretation. The pasuk is telling you the surface symptom; the Midrash is telling you the root cause, the underlying disease.

This approach, I think, also resolves our original question and explains the kal v'chomer Moshe drew.  If Bn"Y, who came from the lineage of the Avos and had a tradition about geulah, still did not listen because the attraction of avodah zarah pulled them in the wrong direction, then surely Pharoah, chief and leader of a culture steeped in avodah zarah, would never listen.