Have you ever looked at the populations of a given state ... looked at the number of people that move in one year and done the math?
California - with the largest population in the United States - and arguably one of the most dynamic saw 120,000 people leave last year ... and another 190,000 people move here for a net change of +70,000 people ... about how many people are stuck in traffic on a given weekend going to 'Vegas from here.
70,000 people is a bunch until you concider that there are like 25 MILLION people in Texas ... and all of them moving aren't moving to the same state and are about 50-50 conservative to liberal (actual number in California are about 54-46%). So if you take that 4% number of extra liberals ... and work that against 25 million you'd need like twice the entire population of California to move to Texas ... every man, woman, and whatever out of San Francisco to move ... you couldn't pitch tents fast enough to house them let alone fit the kids in school, sick people in hospital, cars on the roads, and people in jobs.
Even in a little state like Nevada with a 2% split in the R/D it's a hard thing to do ... despite what you've read on the Internet!