The Big Con: Crackpot Economics and the Fleecing of America by Jonathan Chait is one of the best political books I've read in a long time. If you wonder how the party of Eisenhower and Nixon turned into the party of Dubya and DeLay, Chait explains it. The first section is about how the Laffer curve (a.k.a. supply-side economics) came to be accepted as Gospel within the Republican party despite having little or no credibility among academics. Long gone are the fiscal conservatives, deficit hawks who tried to balance taxes and spending. Now the default solution to every economic problem for the Republican party is to lower taxes and increase corporate handouts (Chait also describes the rise of business lobbyists -- can you believe in 1961 only 50 corporations had Washington lobbyists? -- and the K Street Project).
The second part of the book is more diffuse. Chait describes a number of changes in the political landscape and ties them to how Republicans embraced a radical right-wing ideology while most Democrats haven't moved much on the political spectrum. He reveals disturbing insights about how Washington used to work versus how it works today, things that are all but invisible to the average American. For example, GOP legislative leaders have taken over agendas that used to belong to the committees. Also whereas the legislative and executive branches used to operate independently of each other even when the same party controlled both (which is how "separation of powers" is supposed to work), the Republican legislature was utterly subservient to the Bush administration.
One important piece of the political puzzle that Chait tries to avoid in this book is social issues, though the conventional wisdom is that socially conservative voters are the enablers that put the Republicans in office so they can cut taxes and pass out money to businesses (if that sounds cynical, consider how much talk there is about social issues around election time versus how little Republicans actually address those issues in office).
Chait describes himself as a moderate, but no doubt Republicans would portray him as a seething Marxist (as they often do when challenged). I think the first half of the book has less partisan rhetoric than the second half, but generally Chait stays true to his moderate position. It's hard not to sound partisan when detailing the antics of one particular party.
Although The Big Con was published before the 2008 election, the GOP hasn't changed its ideology so it is still relevant. It pre-dates the teabaggers, but their rabid anti-tax views were formed by Republican operatives anyway. I haven't read Chait's