I just noticed today that Louis J. Budd's _Mark Twain: Social Philosopher_
has been reprinted in the University of Missouri's Mark Twain and His Circle
series:

http://www.system.missouri.edu/upress/twainser.htm

This book was first published in 1962 and has been out of print for decades.
 It actually took me decades just to find a used copy, so I wanted to thank
the editors of the series and the press for bringing it back into print, and
to
recommend it to anyone who hasn't read it yet.

Published four years after Philip S. Foner's _Mark Twain: Social Critic_
(1958 -- perhaps another candidate for reprinting in the series), and
written
partially in response to it, Budd's book is one of the two classic
assessments
of Twain's interest in political and social issues and his expressions of
those
interests in his writings.  Although an enormous amount has been written
about Twain in the last forty years, nothing comparable to those two works
has come out and they remain must-read books on the topic to this day.

Contents (from the first edition -- I don't know if anything new has been
added to the new edition)

1. Political Apprentice
2. Acquiring Reporter
3. A Curious Republican
4. Solid Citizen
5. The Scalawag
6. Uncle Sam
7. The Bankrupt
8. Dollarless Diplomacy
9. The White Knight
10. Conclusion
Bibliographical Note
Notes
Index

It can be ordered through the Forum's TwainWeb Bookstore with proceeds
going to the Mark Twain Project:

http://www.yorku.ca/twainweb/bookstore/

Jim Zwick