At the beginning of the coronavirus outbreak — and for weeks afterward — there was one thing Americans could seemingly agree upon: Anthony S. Fauci.

Today, that’s considerably less the case. While Fauci retains the faith of a strong majority of Americans, opposition from Republicans has crept up steadily over the past month or so, as conservative media figures and now President Trump have increasingly called his advice into question.

Picking up that mantle in a particularly prominent way Tuesday was Sen. Rand Paul (R-Ky.), who spent his time at a hearing of the Senate Health, Education, Labor and Pensions Committee grilling Fauci. Paul suggested that the renowned epidemiologist should not oversell his knowledge about what might become of the novel coronavirus, while questioning Fauci’s caution about reopening the economy and schools.

Trump has also upped his criticism of Fauci over the last 24 hours. After briefly retweeting a tweet that called for Fauci’s firing in mid-April — and downplaying the significant of that — Trump on Wednesday publicly questioned Fauci’s caution in his Senate testimony about reopening the country. Trump said it was “not an acceptable answer” and that Fauci “wants to play all sides.” Then on Thursday morning, he claimed that Fauci had criticized his China travel restrictions.

“I was criticized by everybody, including Dr. Fauci,” Trump said on Fox Business Network. (Whether Fauci criticized it or not, it was hardly “everybody” who criticized the move.)

The twin arguments feed into a growing anti-Fauci movement in conservative circles. And two polls this week reinforce that this skepticism is taking hold: Both a CNN poll and a CBS News poll suggest a significant decline in GOP regard for Fauci’s actions and expertise, when measured against other similar polls of Fauci in recent weeks.

While 84 percent of Republicans said they trusted the information they received from President Trump about the virus in the CNN poll, just 72 percent said the same about the Centers for Disease Control and Prevention, while just 61 percent said the same about Fauci.

The newer CBS poll is even starker. While Republicans trust Trump by an 85-15 margin for coronavirus information, they are now evenly split on Fauci — 51-49.

That split on Trump and Fauci is something that simply didn’t exist even a month ago.

A Fox News poll conducted in late March showed very little difference in GOP perceptions between the two. At the time, 85 percent of Republicans approved of Fauci’s handling of the coronavirus outbreak, vs. 8 percent who disapproved. His plus-77 rating was about the same as that of Trump, for whom 86 percent approved and 13 percent disapproved (plus 73).

That gap, though, has progressively widened over the past month.

A Quinnipiac University poll in early April showed Republicans approved of Trump 89 to 10 and Fauci 77 to 8 — still sterling numbers for Fauci, but not quite on Trump’s level.

By late April, a Gallup poll showed 91 percent of Republicans approved of Trump on the virus, but just 71 percent approved of Fauci.

Early this month, Republicans in a Washington Post-University of Maryland survey said Trump had done an “excellent” or “good” job on the coronavirus by a 79-to-21 margin (plus 58), compared with 68 to 25 (plus 43) for Fauci.

And now, the CBS poll shows the biggest gap yet — at least on the narrower measure of trust.

Until this week, Trump had declined to clash too much with Fauci publicly. But many of his allies in conservative media (and now the Senate) have been happy to pick up that torch and question Fauci’s advice, as they push for a more aggressive reopening of the economy than Fauci has advocated. Trump seems to be edging in that direction, too, and his interview Wednesday suggested it might soon be more overt.

And it seems to have gradually had the intended effect — even as Fauci, to date, retains a relatively strong image with all Americans.