Diverting some Mississippi River water from Louisiana to Southwest states.

I thought the Mississippi River is a record low levels

 

This is the side of "climate change" that no one considers. There will be un intentional consequences and benefits if they do this. There are a lot of ecologies that will change. Some better, some worse, some indifferent and all of them will effect weather downstream of the air flow. New invasive species will be able to invade areas they should not be. A particular carp they are already in a losing battle against will likely be one. On flip side some roaming animals may return to areas they abandoned after having been depleted of water due to city population growth that almost never considers the water that they will need to draw from.
They can talk carbon all they want but until they realize the damage and redirection of natural growth and how it effects the weather none of the stuff they chase after is going to matter much.

 

Midwest state will fight this to the point of secession.

 

Only if they use wind and solar to power the pumps!

It is a bad idea.

Why don't they use de-salination to supply the water from ocean.
Or cover the existing canals to lower the amount of evaporation in transit. Or maybe don't build in the desert to begin with.

 

Sorry, you choose to live in a dry climate, these states already sucked Lake Meade dry, and now these states want to rob the Mississippi River?

 

Actually this isn't a half bad idea, a huge project though but would create a lot of jobs, I've often thought about all the rain we get in the tropics and how it all just runs out into the ocean what a waste of water, why not build huge channels or tunnels to divert the water to regions that don't enjoy good rain fall?

 

I would point you to looking into the balance of salinity in the oceans and how it effects ocean currents, which in turn drives atmospheric systems.