Connecting the GameCube controller to my Wii

I just did the test right now with SSMB
in order: console off, I plug in the controller in position 1 (the closest to the front)
I turn on the console
I use the Wiimote to press A
I put the disc in the drive
I select the game channel, and I start the game with the Wiimote
I place the Wiimote on a table, still on player 1
I take the GC controller, I press start
and there I have player 1 control with the GC controller

however, I don't think I can give control of my Wiimote to player 2 (that might be your problem)
the Wiimote and the GC controller control player 1

after that, I couldn't help you more without being on site and doing the manipulations
Stop failing the Turing test!