The implication is that researchers steer away from topics that would offend the conservatives who have been dealing out the grants. But there is also the unmentionned possibility that researchers steer away from topics or conclusions that might offend their liberal colleagues - particularly if they don’t have tenure. But even tenure doesn’t stop censorship.
Even a famous and tenured Harvard professor, David Putnam, censored himself for a number of years regarding his findings that increased diversity decreased community trust. And Larry Summers as Harvard president sure showed researchers where they dare not go.
In other words, the grant system reinforces the orthodoxy of the day and if the researcher want to keep his snout in the trough he”ll say the right things to the right people.