Updated: Norm Coleman’s razor-thin lead over Al Franken keeps getting even tighter. Yesterday, Coleman’s lead was 477 votes, but as of 10:45 a.m. Thursday, it’s now a 438-vote gap. [At 4:15 took a 590-vote lead, but the margin is again back to 336 by 5 pm. At 8:45 pm, Franken trailed by 236 votes. On Friday, Franken trails by 239 votes. By early Saturday, the gap is 221. And, on Monday morning, the tally is 204.] Forum Communications reports one small reason why: Election officials in Buhl, Minn., reportedly went to bed election night without reporting the tallies for its 550 voters to county officials. Also reporting of results in Duluth was delayed because one precinct, “inundated with hundreds of same-day registrations,” took longer to count.

Could the recount shift victory to Franken’s side? Hard to say, but SenateGuru does the math on what that’d take. Answer: Not much.

Franken needs only to pick up one single vote every 8.6 precincts in order to claim the lead.  Every 8 or 9 precincts, there just has to be one single ballot overlooked, one single ballot that didn’t scan right.

Vote tallies are literally changing minute to minute. Follow the changes at the Secretary of State’s Office.

Update: David Brauer offers some interesting details. Two of every 1,000 optically scanned votes aren’t counted, he writes: “Extrapolated, that means 6,000 votes could enter the pool this time.”

Update: Here’s why the vote counts keep changing, from MPR’s Polinaut:

Secretary of State Mark Ritchie said the Senate vote totals will continue to move as county election officials double check their work. He said the numbers will continue to fluctuate until the County Canvassing Boards certify the election. The deadline for the county boards to certify the numbers is Monday, November 10th. The counties are required to submit their election reports by November 14th to the Minnesota Secretary of State.

The State Canvassing Board will then meet on Tuesday, November 18th to certify the election. At that point, the board will order a recount which is required by state law.