Sen. Barack Obama leads his republican rival, Sen. John McCain in the presidential race nationally, but his national lead over McCain appears to be declining slightly — that’s what the recent Obama versus McCain pre-election opinion polls say.

Obama leads McCain by 6 % points and 3 % points in the latest opinion polls conducted by Gallup Daily Tracking and Rasmussen Reports Tracking respectively. In Gallup Daily Tracking polls, conducted on August 26-28 and August 27-29 respectively, Obama was leading McCain by 8 % points nationally.

Gallup Daily Tracking poll, conducted from August 28 to August 30, showed Obama leading McCain by 6 % points — 48 % to 42 % among the national registered voters.

Rasmussen Reports Tracking poll, conducted on August 31, showed Obama leading McCain by 3 % points — 48 % to 45 % among the national registered voters. According to the poll, Obama has currently a 61.5  % chance of winning the presidential election in November.