While all administrations hide evidence, conservative/republican presidents do it pretty openly. Bush and 9/11 was a great example. I dont know of too many bigger lies/coverups than the information surrounding 9/11 and the "war on terror".

The issue is that something like 1/3rd of americans will eagerly believe anything if it's directed towards the right victims or their party says it.

From the page you linked:

  > "If we stop testing right now, we'd have very few cases, if any," Trump asserted.
  >
  > Earlier in the day, the president, on social media, called “testing a double-edged sword” that makes the country “look bad” but is “good to have.”

It's hard to get what he really want from that snippet .