Environment
The Civil War & Lincoln
Jonah Goldberg proposes federalism as means of peaceful coexistence betweeen the left and right. Trouble is, it has been tried before: Stephen Douglas. The other guy eventually won. Let's stick by Abe's "tough nut to crack."
In California, among other states, the left has long been at work on "independent state grounds" laws. In this regard, opponents of abortion are misguided in their focus on Roe v. Wade, which certainly should be overturned. Overthrowing Roe would permit state legislatures to restrict abortion, but it would leave other, liberal states with abortion rights protected. For more on "independent state grounds" see this book on democracy in California and this article by Edward Erler.
The Sage of Mt. Airy has more theoretical speculations on the meanings of federalism for the right and for the left.
Courts
The unethical investigation (and subsequent 2008 conviction) of the late Senator Ted Stevens (R-Alaska) for alleged ethics violations reveals a crisis in democratic government: When Department of Justice investigators influence elections--in this case, one that gave Senate Democrats a veto-proof majority--they are showing themselves to be the rulers they have in fact become.
In many reapportionment schemes, the legislators pick their constitutents. In the Stevens investigation, where the judge held government lawyers in contempt after the trial, the bureaucrats in effect knocked off a Republican incumbent, who lost by fewer than 4,000 votes a week after the trial. The court-appointed counsel concluded that the prosecution withheld potentially exonerating evidence from the defense. Even Eric Holder had to discipline the lawyers, with one committing suicide. (It should be noted that a Republican Administration might not have been able to control their own staff.)