When I worked as a professor of mathematics in Chicago, my research was supported every year by summer grants from the federal government. This kept me on my toes. These grants supply additional salary and normally require fresh ideas every two or three years. Money coming from outside academia can have a wonderful effect on academics, who often feel undervalued by their own university. No need to engage in political skulduggery or sycophantic posturing to get a higher salary - just convince your scientific peers in other universities that you're really worth that extra money.
Of course, the federal government has to foot the bill, but it wants to support the universities anyway and this method funnels money through those working at the cutting edge. Their extra salary and travel expenses normally form only a smallish fraction of the total grants as the universities soak up large overhead costs. This makes them keen to employ staff who can obtain grants - those whose work attracts good peer reviews. No need for each university to make its own careful soundings from external assessors. It's all done automatically and is perennially updated. Moreover, the government's generous support creates a stimulating environment that attracts foreigners to work in the US. In my department at one time, over half the research faculty were from abroad.
It wasn't always this way. After the First World War, Germany was the place for mathematics. But the Nazis put paid to that and many of the brightest minds moved across the Atlantic. Of course, the Nazis were very stupid, but don't be too smug. Government interference and bureaucracy in the UK are forcing some British academics to seek new pastures. We should be providing an environment to release their creative energies rather than stifle them.