Where is the poll source when Hillary clinton was the democrat, john mccain was the republican, and the margin of error was less than 4.5 on May 2-7, 2007?
CREATE TABLE "connecticut" (
  "poll_source" text,
  "sample_size" real,
  "margin_of_error" real,
  "date" text,
  "democrat" text,
  "republican" text
);
SELECT "poll_source" FROM "connecticut" WHERE "democrat"='hillary clinton' AND "margin_of_error"<4.5 AND "republican"='john mccain' AND "date"='may 2-7, 2007';