The scientists who plan to participate in the march fear Trump will suppress politically inconvenient research at federal agencies.
They know that within hours of his inauguration, Trump's team began scrubbing federal websites of information about climate change.
One of the many incendiary claims that Trump has offered without evidence is that climate change is a hoax perpetuated by the Chinese.
In fact, 97 percent of climate scientists agree that human activity is making the planet warmer and driving disruptive climate changes.
And his choice to lead a panel on reform in higher education is Jerry Falwell Jr., an evolution-denying biblical creationist.
Like Trump, the Republican leaders who control Congress appear hostile to science that doesn't support their political agenda.
By marching for truth, scientists are not being political - they are merely doing their job.