JEFFERSON CITY, Mo.—Republican John McCain has defeated Democratic President-elect Barack Obama in Missouri—the last state to be decided in the 2008 presidential election.

McCain’s narrow victory over Obama breaks a bellwether streak in which Missourians had picked the winning presidential candidate in every election since 1956.

With all jurisdictions reporting complete but unofficial results, McCain led Obama by 3,632 votes Wednesday out of more than 2.9 million cast—a margin of 0.12 percentage points.

Both men spent considerable resources trying to win Missouri, a state that Obama ultimately did not need for his national victory.

Obama won 365 electoral votes. Missouri’s 11 electoral votes will give McCain 173.

Secretary of State Robin Carnahan has until Dec. 9 to officially certify the results.

But it’s unlikely the vote totals will change significantly because no more ballots can be counted. Rather, the secretary of state’s office now will double-check the figures supplied by local officials to make sure no numbers are missing and that the precinct-by-precinct votes have been correctly added.

Once the results are certified, Obama’s campaign would have the option under Missouri law of seeking a re-count because McCain’s victory margin is less than 1 percentage point.

Missouri’s presidential election was its closest since 1908, when Republican William Howard Taft defeated Democrat William Jennings Bryan by 449 votes out of 716,788 cast—a margin of 0.06 percentage points.