What rights, if any, does a defendant have to cross-examine a witness in a trial?

It is undoubtedly true that defendants should be permitted to confront and cross-examine witnesses against them. It is also true that trial judges retain the power to impose restrictions upon that cross-examination, and have wide latitude to preclude "harrassment, prejudice, confusion of the issues ... or interrogation that is repetitive or only marginally relevant." Delaware v. Van Arsdall, 475 U.S. 673, 679, 106 S.Ct. 1431, 1435, 89 L.Ed.2d 674 (1986). After all, what the constitution guarantees is "an opportunity for effective cross-examination, not cross-examination that is effective in whatever way, and to whatever extent, the defense might wish." Id.