Because if you do, all they do is nearly wreck their presidencies seeking a grand bargain, only to get rewarded with this:

Again–and this is worth repeating–Democrats are fools to play this “game.” The facts of life are simple. First, grand bargains are unenforceable. Second, it’s impossible to pass large-scale deficit reduction in a unipartisan way, or really in a bipartisan way. The historical record is quite clear. The unipartisan way lost control of at least one chamber of Congress in 2010 and 1994, and the bipartisan way lost the White House in 1992. In the latter, Republicans simply revolted against higher taxes and disowned the deal (and the principle of raising taxes ever again), in the former two, unified Democratic control came to an end after the passage of bills designed in large part to deal with the deficit. Sure, health care reform did include money for poor people to get insurance, but the sales job and structure were much more about bending the cost curve–which is a worthy goal, but in any event this process creates losers that will strike back electorally. Third, very few people actually care about deficit reduction, and most of those who do are Republicans whose party pays sufficient lip service to the goal to keep them from considering any sort of switch. Fourth, there is little point to sacrificing political capital to lowering deficits that Republicans will just explode with more tax cuts and military spending as soon as they regain power. And fifth, the press will never, ever stop thinking of Democrats as tax-and-spenders (which ironically is supposed to be a badge of fiscal irresponsibility but implies spending that is paid for–it’s not much of an insult, since it’s basically saying “not a Republican” but nonetheless), and Republicans will always be so tortured by debt that they have little choice to keep exploding it until catastrophe forces us to accept a 19th century structure of government, thus eliminating it somehow. But Republicans had pundits at “tortured by debt.”

I do think that Democrats should actually pay for programs they create, rather than just put major new entitlements on our tab a la Dubya. But Obama has played by the Beltway rules on the deficit issue from day one. He’s assumed bipartisan goodwill that hasn’t existed since at least 1990, been comically overeager and optimistic over the possibility of a deal, and proposed many of his own that were frankly horrible and would have torn up his own party if he’d moved forward with them. Above all, he’s seriously misread the attitude and intent of pundits and media opinionators throughout, and the fact that he’s given absolutely zero credit for this by the press is entirely predictable and entirely damning. Regardless of my views, it’s insane for media outlets to act as though Obama has done little more than bicker with Republicans, and yet that’s what they’ve done. I would hope this is a cautionary lesson to future Democratic presidents: don’t bother with grand deficit ideas, because (1) almost nobody cares, (2) the powerful people who do care will never be satisfied and will never give credit, and (3) the people who actually care will never be convinced due to tribal psychology and information flow from ideological networks. Of course, given the imminence of the sequester, it would appear that the rotten fruit borne of this tree has not yet even begun.