A career politician (both Dems and Repubs) will ALWAYS attempt to make government bigger and more important in the lives of its citizens. This means more intrusion into the private lives of every citizen and in turn a more liberal government is created.
The politician gives more money to the voters and in turn gains more power. This process feeds on itself until the whole system implodes. Liberalism leads to socialism which leads to lower standards of living for all citizens.
For an example of Socialism, just look to Europe. Most Europeans have a horrible standard of living when compared to the USA.
Bottom line, the more power a government has, the worse off the people are. We are seeing the beginning of the end. Most of us won't be alive to see the end, but our grandchildren just may.