I think the democrats are going to regret this. Two of the four will definitely eat the democrats alive and the other two probably will, too. These guys did absolutely nothing to instigate anything and they know it, and they know the dems know it, too. The dems will have zero leverage over them.
The best response would be to ignore the subpoenas. The left can do it, so can we. Send someone out thinking they have a right to arrest someone for ignoring the subpoenas? That's exactly what the 2A is for.