Possible Clues:

• Founding patriarch of the Flying Wallendas
• Communism theorist Marx
• Rove in the political arena
• — Marx, socialist
• N.B.A. coaching great George ___
• Communism co-founder Marx
• Marx who wrote 'All that is solid melts into air'
• With 33-Down, co-author of "The Communist Manifesto"
• Jazz player Malone
• Malden of movies