What is the test for excluding evidence of an accused's defense?

"Ordinarily a criminal defendant's attempt 'to inflate garden-variety evidentiary questions into constitutional ones [will prove] unpersuasive. "As a general matter, the '[a]pplication of the ordinary rules of evidence . . . does not impermissibly infringe on a defendant's right to present a defense.' [Citations.] Although completely excluding evidence of an accused's defense theoretically could rise to this level, excluding defense evidence on a minor or subsidiary point does not impair an accused's due process right to present a defense."'" (People v. Thornton (2007) 41 Cal.4th 391, 443.)