But there’s another reason health care reform is much harder now than it would have been under Nixon: the vast expansion of corporate influence.

We tend to think of the way things are now, with a huge army of lobbyists permanently camped in the corridors of power, with corporations prepared to unleash misleading ads and organize fake grass-roots protests against any legislation that threatens their bottom line, as the way it always was. But our corporate-cash-dominated system is a relatively recent creation, dating mainly from the late 1970s.

And now that this system exists, reform of any kind has become extremely difficult. That’s especially true for health care, where growing spending has made the vested interests far more powerful than they were in Nixon’s day. The health insurance industry, in particular, saw its premiums go from 1.5 percent of G.D.P. in 1970 to 5.5 percent in 2007, so that a once minor player has become a political behemoth, one that is currently spending $1.4 million a day lobbying Congress.

That spending fuels debates that otherwise seem incomprehensible. Why are “centrist” Democrats like Senator Kent Conrad of North Dakota so opposed to letting a public plan, in which Americans can buy their insurance directly from the government, compete with private insurers? Never mind their often incoherent arguments; what it comes down to is the money.

Given the combination of G.O.P. extremism and corporate power, it’s now doubtful whether health reform, even if we get it  which is by no means certain  will be anywhere near as good as Nixon’s proposal, even though Democrats control the White House and have a large Congressional majority.

And what about other challenges? Every desperately needed reform I can think of, from controlling greenhouse gases to restoring fiscal balance, will have to run the same gantlet of lobbying and lies.

I’m not saying that reformers should give up. They do, however, have to realize what they’re up against. There was a lot of talk last year about how Barack Obama would be a “transformational” president  but true transformation, it turns out, requires a lot more than electing one telegenic leader. Actually turning this country around is going to take years of siege warfare against deeply entrenched interests, defending a deeply dysfunctional political system.