@engineer,
Of course it changes due process.
It puts the defendant in the position of proving his innocence by affirmatively proving consent. With due process in a criminal prosecution, the prosecution has the burden of proving guilt.
This puts defendants in a very difficult situation... this is a pressure that defendants of other crimes are not subjected to.
And think about the standard this is setting. The last time you had sex, did you get a clear verbal affirmative statement by your partner before you started having sex? Or was consent implied.
For that matter, the last time you had sex... did
you give a clear verbal affirmative statement of your consent?
(I didn't.... but I don't think that means I was raped.)