mulishly

Instead, we saw Obama stand his ground, not mulishly but stylishly.

Loving tradition, he dislikes change, and often stands mulishly in the way of necessary progress.

And as for my managing Peter, they know perfectly well that, though he's a darling, he's just mulishly obstinate.

This lad, usually docile to any rein, had suddenly grown mulishly obstinate.

Wardwell stayed a while, arguing mulishly, but Jim Ray did not move from his position.

A treasonous step on this mule of a Bookseller's part, thinks Voltaire; but mulishly persisted in by the man.