Wikipedia

When an arguer combines two positions, one easy to defend and the other one controversial and much harder to defend. When challenged on their position, they will claim to only advance on the modes position.

Example:
A: Homeopathic medicine can cure cancer. (bailey)
B: There’s no evidence showing homeopathy is effective.
A: Actually there are many ways for people to be healthy besides taking doctor-prescribed drugs. (motte)