IN A BATTLE of free-spending, self-propelled millionaire candidates, state Sen. Robert Graham (D), 42, seems to be pulling away from Jack M. Eckerd (R), 62, and is favored to succeed retiring Gov. Reubin Askew (D). Democrats came out of their primary more united than the GOP, and Eckerd, owner of a drug store chain and former General Services Administration chief, has stumbled in the same fashion that cost him victory in two previous statewide races. Weekend polls in The St. Petersburg Times and Miami Herald peg Graham's lead at 9 to 12 points.

But Democratic prospects in House races have dimmed. Rep. Richard Kelly (R) appears headed for reelection despite an earlier threat. Rep. J. Herbert Burke (R), who was arrested and fined for disorderly conduct outside a nude go-go joint, has drawn an opponent, Sheriff Edward J. Stack (D), who at 68 is three years older than Burke and has liabilities of his own.

State Rep. Earl D. Hutto (D) is favored to succeed retiring Re. Robert L. F. Sikes (D), but the fight for the seat of retiring Rep. Paul G. Rogers (D) is rated a tossup. State Rep. Bill Nelson (D) could give his party a gain if he defeats ex-Sen. Edward J. Gurney (R) for the seat formerly held by Rep. Louis Frey Jr. (R). But veteran Rep. Claude Pepper (D), 78, is getting more of a challenge than expected from Al Cardenas (R), a 30-year-old lawyer and leader of Miami's large Cuban community.