I cut the recipe i half made this and made this two weeks go and they were great. This morning made them and they came out flat What might have...

When I hear "flat scones", I almost always find that a heavy hand is to blame. Err on the side of undermixing when it comes to scones and biscuits. Were they also dense? I have scone recipes that don't rise vertically, but still have a lovely open crumb and delicate texture. These don't look like what many Brits/Scots would consider scones, so I'm also not sure what your expectations are.

I don't know about your area but it's been particularly rainy here the past few days. If they have worked previously, it's possible that factors beyond your control (humidity) were to blame!

I can think of a couple of possibioities right off the bat: you overworked the dough? or your baking powder and/or soda was old. Plus, if you check out the photo of the scones -- which BTW sound divine -- they don't look as if they raised a whole lot. That doesn't surprise me, as cornmeal is lacking in gluten which helps bread products to rise.