While there are no recent polls at RCP, at the end of October Trump was leading in Texas.
And while you contend the deep south is a problem for Trump, the polls don't bear that out.
As for the "SEC Primary" on March 1st, again all of those delegates will be proportionately allocated.
It's March 15th with Florida, NC, Missouri and Ohio then the race will likely be decided. They are all winner take all.
The polls had Mitt Romney edging out Obozo before the election.