CREATE TABLE table_66596 ("Name" TEXT, "Labour" FLOAT, "Conservative" FLOAT, "Political party" TEXT, "Electorate" FLOAT, "Constituency" TEXT)

What is the smallest electorate for the Conservative party in South West Devon constituency, with over 2 conservatives and a name of Plymstock Radford?
SELECT MIN("Electorate") FROM table_66596 WHERE "Political party" = 'conservative' AND "Constituency" = 'south west devon' AND "Conservative" > '2' AND "Name" = 'plymstock radford'
SELECT MIN("Electorate") FROM "table_66596" WHERE "Conservative" > '2' AND "Constituency" = 'south west devon' AND "Name" = 'plymstock radford' AND "Political party" = 'conservative'