In the 26 largest counties with 75% of the voters Republicans won by 332,590 votes in 2012, but the Democrats won by 262,992 votes in 2016. The Libertarian vote increased by 161,147 votes at the same time representing potential swing voters. Statewide the Libertarian vote went up about 195,000. If you look at actual data Democrats have made inroads.
In the 228 smaller counties the Republicans won by 929,129 votes in 2012 and 1070171 votes in 2016 a 141,042 improvement.
Based on linearly extending the simple 2012 to 2016 trend and assuming a 60% midterm turnout for both parties the Democrats would win the big counties by 559,543 votes. A 60% decrease in smaller county turnout from 2016 would give the Republicans a 642,102 vote advantage there for a net win of 82,559 votes statewide. This is before factoring in what the swing Libertarian vote does, or if there is a blue wave, or that 10% of Republicans have abandoned the party, and many other bad trends for the Republicans.
A recent poll put Cruz's support in rural areas at 66%, when the R advantage in the 228 smallest counties was 72.5% in 2012 and 74.6% in 2016. If Cruz only has 66% support in the 228 smallest counties, not all of which is rural by the way, he only wins them by 443,205, once again assuming a 60% turnout by both sides.
I am starting to think there is a realistic possibility that Beto will have a 800,000 to a million vote advantage in the 26 biggest counties, and the rural vote will be unable to make up the difference. That comes to a 6 to 10 point win.
I am hoping that this will lead the Democrats to victory in the Lt. Governor and Attorney General races, along with flipping 3-5 US congressional seats. It is regrettable that the Democrats failed to run a decent candidate for Governor, because Beto's blue wave might have pulled a good candidate across the line.