There is almost total unanimity in the Natmosphere around something that goes like this: "signing Tex is the best thing that could happen to the Nationals, and we should do whatever it takes, and we love him so much, and what could be better than committing to him for 8, 9, 10 years or whatever it takes we just love him so much that there's no imaginable downside to this signing..."
My prediction: if we do not sign him, the overall mood of Nationals fans will within about five minutes become: "he obviously never wanted to be here in the first place and so therefore why should we want him and he's going to be crap by the end of that contract anyway, I mean his PECOTA comps include Willie Aikens for god's sake and he was out of baseball at 31!, and besides he'll probably get hurt, and that's all we need, so good riddance I wish we hadn't even offered that jerk a contract in the first place good luck in [Boston/LA/NY] ya rotten bum."
Not saying that's right or wrong--rabid loyalty to the home team is what fandom is all about. But that's what I expect. It happened to Crow, and I think it'll happen with Teixeira.
Of course the truth is in the middle. Tex is a wonderful player, but there's a big risk associated with this signing, and the downsides are very real and potentially enormous. I don't think anyone should be unequivocally cheering for this to happen. Look at what ARod did for (to?) the Rangers. You can hope for it to happen and get excited--why not get excited and hope for the best?--but nobody should be thinking that this would be all upside with no risk. If it happens, we should all take a deep breath and pray long and hard for health and a favorable aging curve.