Sorry that this is coming so late. I saw your question right away, but this became quite long-winded and I had to write this in between my work. Your question actually touches on the thesis on which I am working right now so I thought I gave you an insight in my current work and my evolving thoughts on this matter. Keep in mind, this is totally work in progress, so perhaps it's not as concise and comprehensible yet as I wish it to be in the end. I will also give you a short summary of two of the most important events of the era, the Reform Acts of 1832 and 1867, because they are instrumental in understanding British politics of the era.

First, your observation is spot on. Since the Civil War and the Glorious Revolution in the 17th century England (and by extension Great Britain since the Act of Union 1707) has enjoyed remarkable institutional stability. As a matter of fact modern British citizens live in the same state as their ancestors did in 1733 or in 1867 -- at least by legal definition. Compare that to the five incarnations of the French Republic we have seen in the last 124 years, the three German Reiche, the end of three of the world's foremost monarchies, the rise and fall of the Soviet Union, and entire states vanishing and re-appearing on the continent. Even if we limit the scope to the 19th century alone (which I intend to do in the following) the difference is explicit. Great Britain was largely exempt from the revolutions and the violent turmoil of the 1830s and 1840s. It was not hit by the wave of Anarchist terrorist attacks afflicting continental Europe in the late 19th century. The last violent, armed uprising the Kingdom had seen was the relatively minor Newport Rising of Chartists in 1839.^1

Keep in mind, all the while Great Britain was rapidly industrializing, experiencing social upheaval of unforeseen proportions. The population quadrupled over the course of the century, and especially the new centers of this industrial revolution grew the most comparatively. In 1845 more Britons lived in cities than in the countryside for the first time, in 1891 already three-fourths of the population were urbanites. Meanwhile, Britain's national product octuplicated in the same time, a generation of Britons could experience significant technological and economic advances in their lifetime. However, due to the urban nature of this new society its pauperism, inequality, and injustice was increasingly noticeable to Britons. Just look at the picture Dickens paints of 19th century London! We can reasonably state that Great Britain had her fair share of social problems not unlike or possibly even worse than its continental neighbours. Karl Marx, living in exile in the UK, saw the country on the brink of proleterian revolution, in fact, his theory considered the advanced industrialization of the UK as the most probable staging ground for socialism.

In the view of this the apparent peacefulness of Victorian Great Britain is quite remarkable. Indeed it prompted the German social historian Bernd Weisbrod to speak of an English Sonderweg into the Modern Era (following the Sonderweg school of thought of German historiography). I wouldn't go so far,^2 but I would argue that the political landscape of Victorian Britain is, on both sides of the political spectrum, strikingly dominated by the idea of reform and gradual change rather than revolution/reaction. The two dominant parties in the Upper and Lower House, the Conservatives and the Liberals, were both engaged in continuous reform of the way Britain was governed -- although their respective reasons were completely different. Likewise, the mid-century Chartist movement, and the emerging Labour movement in the second half of the century both generally favoured reform and "socialism by ballot" over revolution.

However, at the beginning of the 19th century Great Britain was not a democratic country by any means and did not perceive itself as such explicitly. The French intellectual Alexis de Tocqueville, widely known for his writings on democracy in the young United States, presented Britain as an example of what he called a "functioning aristocracy". This assessment fitted perfectly to the attitude of Britain’s ruling class. The aristocratic elite believed the right to vote was more of a privilege than a basic right. A privilege either inherited by birth or earned if one proved himself worthy. The very notion of democracy was in the eyes of the establishment tied to "mob rule" and the excesses of the French Revolution. The elite deemed large parts of the population simply unfit to participate in something as sophisticated as politics, because of their low education and their dependence on employers, landlords or similar superiors. Politics was reserved for respectable gentlemen, who could afford it. The lower class and the middle classes were effectively excluded from political participation.

The first large inroads were made by the Reform Act of 1832 which extended the electorate to the wealthier middle-class (the way this was achieved is complicated, it was mainly through lowering minimum income/land ownership requirements for voting) and strengthened the importance of the newer cities at the expense of so called "rotten boroughs" -- sparsely populated or uninhabitated rural constituencies which were controlled by a lord and afforded him disproportionate influence. The Act was driven through parliament by the Whig faction, who at the time dominated the House of Commons, against the opposition of the Tories in the House of Lords and the King. It was a watershed movement in British political history. The House of Commons asserted its dominance over the House of Lords and the King and initiated the long process of democratization of the Kingdom. (Although no one at the time would have said it this way.) Whigs and Tories at this point were rather loose factions or lobbies of parliament members (MP), but the emergence of popular elections and the need to actively campaign for voter support in the post-1832 era transformed them into Britain's first distinct political parties. The Whigs, with their base in the rising urban middle class, industrialists and merchants, became the economically and reform-minded Liberals, while the Tories, based in the rural areas, the aristocratic elite, and "old money", became the Conservatives who were concerned with preserving the perceived traditions of Great Britain in the face of change and "Whig rashness". After 1832 the stage was set for Victorian era politics.

Naturally, the call for reform was not entirely satisfied by this. The lower and the lower middle classes, especially the rapidly growing urban proletariat, still didn't have a say in British politics. They made themselves be heard through participation in frequent mass gatherings, demonstrations if you will, of unprecedented size in which they called for change. The largest and most well-known movement of this kind were the Chartists from the 1830s to the 1850s. They took their name from the People's Charter of 1838, a document which called among other things for the introduction of universal (male) suffrage, the secret ballot, and the abolition of property requirements for MP. Although Chartism is linked to occasional riots, it was by and large a peaceful movement which tried to achieve its goals by petitioning the parliament for reform. (Petitions signed by millions of Chartists were read out in the House of Commons.) Although running out after the 1850s Chartism without achieving immediate goals further established the continued need for political and especially electoral reform in the minds of Victorian politicians. The next big step on Britain's road to democracy, the Reform Act of 1867, is part of the Chartist legacy.^3

(to be continued ...)