What are the Differences between the Nature of the Party Systems in the United Kingdom and United States

-Two Party System much stronger in US than UK 2 Main UK Parties fall below the nearly 100% Seats held by Democrats and Republicans -Stronger Regional Variations in the UK than the US. Democrats and Republicans essentially Dominate all States in the US. In the UK, though, the Devolved Assemblies are not Dominated by 2 Parties. SNP and Plaid Cymru have formed Governments in respective Countries since Devolution in 1997 -2 Party System is Characterised by the Pendulum Effect in the UK. One Party holds essentially All Power, but then it swings to the Other Party, which takes over the government. In the US, 2 Parties can be Powerful, in times of Divided Government