We don't... the Constitution tells us so.
Bash... I know that quote floods pro-healthcare sites; but I doubt it's real. Even if it is, I doubt very much that Jefferson meant the federal government should be in charge of either. Love how libs find a little quote or letter, and totally distort the meaning.
He has, however, said this: A wise and frugal government, which shall leave men free to regulate their own pursuits of industry and improvement, and shall not take from the mouth of labor the bread it has earned - this is the sum of good government.
In fact, here's something that speaks to the heart of the discussion - also from Jefferson: I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them.