Republicans tend to favor big, impressive science projects. While the Democrats have a portion of their constituency which believes, against all numerical proof, that money spent on space science could cure world hunger. This stereotype is only partially true but to the extent it is true the divided government result is great for science. This ensures that there is no constituency in Congress that will be able to agitate for cutting budgets for organs such as NASA, the Department of Energy (high energy physics), the National Science Foundation (so many things) and so on.

What is surprising about the United States of America, and many other countries in the new world can be how powerful our legislatures are. If one party or constituency had a supermajority in congress that party or constituency has the power to impeach judges, impeach the president, enact any law that they can agree on, declare war, make peace, levy taxes etc. The representatives of the people and the Senators of the United States in congress assembled have a power that is kin to that of the British Monarch in the 1770s. Congress can make a law that forbids a given scientific activity, funds or defunds anything if it has such unity.

Such is why the founders of our country made certain that there would rarely if ever be such unity of government.  Science thrives in freedom and freedom in the United States depends on no party or group gaining the power to oppress or censor others.