I think at this point, state Sen. Steve Cohen is the likeliest nominee. That won't particularly play well with Black voters, as Cohen is very Caucasian and Jewish (he is also regarded as the single most liberal member of the legislature). If only we could lure someone like Rod DeBerry, the Black Republican who hastened Harold, Sr's retirement in '96, into the race. I have to imagine a great number of Black Democrats will not vote for Cohen in the general (nevermind the anti-White bias, but there still remains considerable anti-Semitism in the Black community, fanned by their leaders), so that also could potentially depress turnout for Junior.
That would help Ed Bryant (should he win the primary) in November.
What I am about to say may sound crazy, but I think that the only rational thing for Harold Ford, Jr. to do is declare that he will indeed run for reelection to the House while simultaneously seeking the Senate seat. Ford can't afford having Cohen on the general-election ballot potentially depressing black turnout and otherwise creating an upheaval in Memphis when every man, woman and child there needs to be working for his Senate win if he's to have any chance at all. He might take some lumps for not being "confident enough" to leave his House seat, but he can claim that he was asked by his constituents to run for reelection so as to eliminate the possibility of a divisive House primary tht might hurt the Democrats in the gubernatorial and Senate races, while still having the intention of winning the Senate race and serving all of the people of Tennessee. He could also promise to announce his resignation from the House, effective January 3, 2007, the moment that he is certified as the winner of the Senate race, allowing time for a special primary in late November and a special general in mid-December so that the new Congressman may be sworn in on January 3 with the rest of Congress. (How are special elections run in TN, DJ? Does everyone run in one ballot and the top-two guys (regardless of party) go on to the run-off if no one gets 50% (as is the case in some states that don't otherwise have a run-off)? If that's the case, then a special election would reduce the odds of Cohen being elected to the House, since the general would likely feature two Democrats, Cohen and a black guy.)
As for the legality of Ford running for both races simultaneously, I'm sure that TN law prohibits him being on both ballots simultaneously, but I believe such a restriction violates the U.S. Constitution. When states passed term-limit laws for Senators and Representatives, the laws did not say that the person could not be elected to more than X terms (which even the states knew would be unconstitutional), bu that the person *could not appear on the ballot* for more than X terms. The Supreme Court ruled that states could not add qualifications for Senators and Representatives beyond those contained in the Constitution (age, residency, years of citizenship), and that denying candidates access to the ballot because of an extra-constitutional qualification violated the Constitution. So if I were Harold Ford, Jr., I would file to run for reelection.
Remember, while a person may not be able to serve simultaneously as Senator or Representative, it's far different to deny him the opportunity to run for both offices and then deciding where to serve. If a sitting Senator who is not up for reelection runs for the House, he can decide if he wins which seat he'll keep; running for both seats would be the same thing.