When someone says they are done, they probably are. You need to focus on your and your child's best interests. That can only be achieved by you dealing from a position of strength. This means that she needs to see you start pulling away. You can hope for the best, but prepare for the worst. You need to start distancing yourself. You need to be vetting attorneys and laying the groundwork for the separation. You need to do some very visible things for yourself, such as join a gym, new hairstyle, new wardrobe, new friends, etc. You need to start being what she wants you to be but** without her**. If this doesn't jolt her back into reality, nothing will. Even if these things are unsuccessful in saving your marriage, these are things that you need to do to look out for yourself, your child, and insure a successful transition into your future. Best of luck.
She has already let the cat out of the bag. She hopes to knock the lone R out, so she can run unopposed in the general. The lone R has a good reputation, and is generally well respected, so hopefully her slimy stunt is ineffective.
A wall is needed. Not only does it visually set a tone, it is a force multiplier and an important tool for border enforcement efforts.