(WDCpix.com)

Norm Coleman isn’t the only obstacle to Democrats wielding 60 votes in the U.S. Senate. Edward Kennedy’s battle with brain cancer and Robert Byrd’s staph infection have effectively whittled an otherwise filibuster-proof majority down to 57 — for now.

Byrd, the 91-year-old senator from West Virginia, will be missing from the Senate for at least another week after going to the hospital three weeks ago, Politico reports, and Kennedy’s return isn’t set.

The Massachusetts Democrat is 77 and has served since 1962, a span three years shorter than Byrd’s all-time record for length of service by a U.S. senator.

Their absences, along with that of Coleman challenger Al Franken, have hamstrung Democrats on legislation from the Employee Free Choice Act to healthcare reform, as well as confirmation of a key Justice Department nominee.

Coleman has kept his own hopes of returning to the Senate alive by appealing two decisions against him, first from the State Canvassing Board in January and then by a special election-contest judicial panel in April. The Minnesota Supreme Court could issue a ruling on that second appeal as early as today.