No.
If Holder leaves, he will be replaced with another just like him.
The leader is the only one that matters.
If val/jar can wheel and deal her way into giving up holder in exchange for our(the House) votes on amnesty she will probably do it.
Remember its all always political. They never do anything unless it is politically advantageous.
If Obama finally does decide to jettison Holder, he can dust off Nixon's speech of April 30, 1973, announcing the resignation of Haldeman and Ehrlichman, "two of the finest public servants I have been privileged to know" (or something very similar).
If Holder does go, it will be further grist for the MSM theme that opposition to Obama is all about race. Conservatives just want Holder out because he's black, not because he's incompetent, dishonest, racist, and hyperpartisan.