Currently Reading:

Samuel B. Griffith II
The War for American Independence: From 1760 to the Surrender at Yorktown in 1781.
Urbana & Chicago, University of Illinois Press, 2002.
(Orignially published as: In Defense of the Public Liberty, Garden City, N.J.: Doubleday, 1976.)

The last paragraph from the book's Preface describes a distinctive feature of this book:

"The purpose of this book is to attempt to place the American struggle for independence in the context of the period in which it took place. To do this in an appropriately objective and comprehensive manner requires first that one accord developments of policy and strategy in Great Britain and France more attention than these generally receive, and second that one allow the actors to speak, to the greatest degree possible consistent with relevance, to the subject of the historic drama in which they took part. My thesis in this latter respect is that selective use of apposite quotations is to be preferred to a presumptuous indulgance in unfounded speculation as to what the actors may have thought or felt."

The book indeed contains much more detail on (a) British politics, and (b) diplomatic interactions between Britain, France, and America than in, say, Middlekauff's book. I find the coverage of British politics - the policies of George III and his Ministers in Parliment, and how they persued those policies - especially enlightening.

A quote from Barbara Tuchman on the back cover:
"... Griffith has made it, for once, a two-sided war."

This last quote reflects a most distinctive feature of the book: current history, with the benefit of hindsight, makes the success of the American Cause appear a foregone conclusion. However, given the place I'm at in the book right now, in 1776 the Americans look pretty weak, despite the long-term strategic weaknesses of the British in attempting to fight the war.

The years 1775 and 1776 were full of dark days for the Americans:
[a] George Washington spent the winter of 1775-1776 surrounding Boston, occupied by the British, in a standoff. This followed the initial successes of American militias in the Battles of Lexington and Concord (19 April 1775) and the Battle of Bunker Hill (actually Breed's Hill) (17 June 1775) - "Bunker Hill" a success for the Americans in the sense that they inflicted massive casualties on the British, although the Americans withdrew from Breed's Hill in the evening after the fight. Washington was appointed Commander in Chief by the Continental Congress on 19 June 1775 and proceeded to Boston to organize the American resistance; however, Washington had no army. During the Winter 1775-1776 Washington had a very weak & poorly supplied army (the various state militias had no long-term obligations to serve and went home) and he would surely have been defeated had the British ventured out of Boston and attacked.
[b] An American expedition to Canada to attempt to capture Quebec, although started promisingly in the Summer 1775, ended in complete failure in January 1776.
[c] The British abandoned Boston in March 1776 after Washington started artillery bombardment of the city. Where were the British Army & Navy going? The Americans' best guess was New York.
[d] However, some British forces went to Charleston, South Carolina but by great incompetence failed to capture the city (May/June 1776). This British force rejoined the main British force assembling in New York harbor. By now the British had been greatly reinforced.
[f] Now occurred one of the Americans' greatest defeats, the Battle of Long Island (late August 1776), and by mid/late September 1776 the British occupied Manhattan. Washington's armies were on the run in New York.
[g] Also in the Summer 1776 the British started to assemble a large army in Canada which they planned to sweep South and connect with their forces now in Manhattan.
[This is as far as I've gotten in the story as of today.]

British long-term strategic weaknesses:
[a] British policy ignored the British constitutional tradition which the Americans had inherited and now defended.
[b] The communication lag between events in America and the receipt of news by the British government in London - major decisions were made by the King and his politicians in London rather than by the British generals in America.
[c] British government expected to fight a cheap war that would end quickly.
[d] The British lacked the money and manpower to fight a long duration war on a continental scale an ocean away from home.