Reactionary, White Russia? Stalin won't be part of that, or upon taking over, it ceases to be White. An SR/Black Russia? Possibly. He doesn't have the temperament or appearance, and possibly not the charisma, to win elections, though.
If the Bolshie coup fails, you probably get an SR/Black Russia rather than a White one, which Stalin won't be terribly interested in joining but won't feel an urgent need (or ability) to kick over. So he falls back on old habits of thievery, extortion and smuggling. Pretty soon he's Russia's answer to "Lucky" Luciano or Al Capone, the actual power running things in Georgia, Abkazia, Ukraine and Belarus, without strong inroads in Russia proper...and just possibly, when the Depression causes a government failure in Russia, he'll be the one in a position to pick up the pieces.