I would argue it started well after Bryan. Grant did nothing to curtail federal pork going to big business. In fact it got even worse under his administration. By the time of Harding and Coolidge, Republicans had mostly cooled it on massive government handouts to big business though they were perfectly willing to go fight several small wars in the Caribbean and Latin America on behalf of major corporations.
FDR was the first really really big government type from the Democrat party. The South supported him because A) he was a Democrat and they sure as hell were not going to support Republicans after the way the Republican party had treated them and B) FDR was THE first president who put more federal money into the South than he took out of the South. Literally. THE first one. By then the South had been reduced from being the richest section of the country to being the poorest. Southerners may not have liked big government but after having money sucked out of their wallets for about 140 years they didn't mind when the money flow from Washington finally reversed itself. I figure we've still got a long long time for that to continue before we can call it even.
Bryan was the first Big Government Canidate. The New Yorker Cleveland was the last Small government Democrat.Grant was for hard money, as was Garfield and Authur. Benjamin Harrison WAS a big government guy. Wilson Nationalized industries and got us into a War we had no busniess being in.
So big intrusive government is ok as long as MY section or area gets it? That is how we got where we are today. The TVA eas completly Un- Constitutional, as was all of fdr new facist deal.