This book provides a fresh reassessment of English politics and political culture during the Commonwealth-the brief period of parliamentary republican rule between the execution of Charles I and Cromwell's seizure of power.
Kelsey looks into the public image the Rump Parliament showed when it was governing the Commonwealth between King Charles's execution and Cromwell's coup - the public pageantry, the manner in which they received ambassadors, how they disposed of or repurposed the royal property, and more. He argues they were trying to build a new republican public image for themselves, which built on native English common-law traditions rather than the more classical Republican model the United States appealed to; which has led other historians to not notice how they were building that model.
I like this detailed argument, and I'm convinced the Parliament was doing something. What they were doing, though, I'm not sure - I'd want to analyze their response to the Levellers, among other things, before judging how they saw themselves. But if Kelsey's argument is correct, I think it represents a fruitful possibility which was too-quickly choked off in Cromwell's coup. I do want to read more about the English Civil War.