Once again people underestimate the attraction of the Jacobite movement and of the House of Stuart. A Stuart restoration at this point is absolutely possible, provided the proper scenario can be set up. To begin with the early Hannovarians (George II and George II) were never popular and neither were their puppet masters, the Whigs. Most books I've read, some of which are entirely opposed to the Jacobites, agree that if there had been a full scale uprising in England the Hanovarian-Whig alliance would be very hard-pressed to defeat it.
The problem was the Tories and Jacobites refused to rise without a French army to act as a nucleus for their revolt. If the French landed regular troops then chances are very high that the Jacobite Peers would rise their tenants and, as promised so many times before, march on London. Whether or not the Franco-Jacobite force could defeat the British army is the real question.
From what I remember in 1744/1745 there was only 10,000 active troops in Britain, but 7,000 were deployed to defend London and South East England. Now going by the lowest estimate of French troops, they would be landing around 6,000 men, close to the number of British troops in southern England. Not sure how many Jacobite forces would be risen in support, but lets say it equals the number of French troops, so that's 12,000 or so Franco-Jacobites vs 7,000 regular troops. Of course in the even of an invasion Parliament would call up the militias, which would greatly augment the number of British troops, at least on paper.
Of course, the French are led by the brilliant Maurice de Saxe, arguably one of the greatest living generals of the time. Leadership might be enough of an edge to give the Franco-Jacobites their needed victory. Assuming they crush the army in a decisive battle and the road to London is open, the situation becomes a siege of the capital, which would be very much difficult unless they get traitors to let them in the city and secure key sites, like the Tower of London. Even if London turns into a siege without traitors within the city, chances are Londoners are going to be in a panic and the economy is going to be in a free fall. There's a chance that this could cause a Parliamentary coup that brings the Tories to power, who offer to make peace and restore James III as King.
Just remember that most of the English population was apathetic to who sat on the throne and probably wouldn't care as long as their lives aren't directly affected, the Glorious revolution and the 1715 rising basically proved that. The entire thing was basically a fight among the aristocracy and merchants, not the common population.
