Try reading some polls yourself.
From your PDF link, you pick out "conservative Republicans" at 51 percent, and leave that hanging.
A bit more from the same source:
Believe in teaching creationism instead of evolution:
Republicans--43 %
Democrats--37 %
Conservative Republicans--51 % (your figure)
Moderate/Liberal Republicans--31 %
Conservative/Moderate Democrats--39 %
Liberal Democrats--30 %
Well. Not that cut and dried, is it?
As for who actually believes in evolution:
Republicans--40 %
Democrats--53 %
That's a bare majority, pal, and of that 53 percent, 20 percent of those think that the evolution was guided by a supreme being.