In the case of ‘New California’, it would likely end up with two GOP guys (I do agree, it might create a RINO or two).
The bigger question here is the attitude around the US states where regions are deeply divided.
Take Oregon. The real Democratic base is the northwest part of the state (around Medford and Portland). The entire eastern part of the state and south part along the coast? Mostly leaning toward the GOP. The real population around the state though...is mostly centered on Portland and four other significant cities....which are urban-magnets for Democrats. The state really ought to be into at least two states...maybe even three.
Take Virginia. If you took away voting numbers in Fairfax, Arlington, and Alexandria...the state would typically be around 60-percent GOP, with Norfolks and Richmond being the Democratic base in this scenario. But the bulk of the rest of the state is solid GOP.
It would serve us all well to redefine the mission and purpose of Senators....allowing only one per state, and allowing states to split into two or more states, if voted upon.
I don’t think you know where Medford is...
You would need to turn NYC into the next Hong Kong.
Add Roanoke & Albemarle/Charlottesville to the VA Democratic base.....
Same situation exists in the State of Washington. Instead of having the border run horizontally along the Columbia River, the two states should be divided vertically along the Cascade Range. Put Western Washington and Western Oregon into one state and call it Washington. Put Eastern Washington and Eastern Oregon into one state and call it Oregon.