Although absentee and missing ballots may yet vault Al Franken into the U.S. Senate, it's no secret he needs to have higher-quality challenges to close his current 344-vote deficit with Norm Coleman.

Instead, Coleman's challenges are better, a new MPR analysis indicates.

The station looked at 1,000 contested ballots released by the Secretary of State — about a sixth of the current total — and determined 350 were "clearly" Coleman votes versus 330 for Franken.

If Franken was right and Coleman's challenges more frivolous, Coleman's number would be lower. (Another 100 votes went to neither man, and 206 were unclear. Franken might hope to gain in the latter pile, but that's highly unlikely.)

Bottom line: if this substantial sample holds true, Coleman's lead would likely increase after the State Canvassing Board meets. And that would greatly lengthen Franken's already-long odds of winning via absentees and missing ballots.

Update: Via Twitter, Jeff Rosenberg offers a fair caveat — we don't know how representative the 1,000-ballot sample is. The pile may contain more Franken challenges, which would inflate Coleman's "clear" numbers, even though the Republican has challenged more ballots.

My only comeback is that one-sixth is a large sample size, so the SoS pile is more likely to be representative.