How did the Columbian Exchange change the lives of people in Western Europe politically?

I assume you mean the impact on Western Europe. The impact
of the Columbian Exchange was at best indirect and did not occur quickly. With the
Columbian Exchange, the diet of most people in Europe improved substantially, primarily
due to the introduction of potatoes, maize, etc. This improved diet resulted in fewer
infant deaths and healthier individuals, the result being an explosion in the European
population. This population explosion was a direct cause of the Industrial Revolution.
The industrial revolution led to the development of a new class, the working class
(Marx's "proletariat.") The working class became politically active which resulted in
increased participation in politics; a primary example being the increased importance of
the British House of Commons.

Diseases were an important
element of the Columbian Exchange, but did not lead to significant political
impact.