President Donald Trump’s campaign to discredit the special counsel’s investigation may be working: A new Politico/Morning Consult poll puts Robert Mueller’s favorability at just 32 percent.

More people — 36 percent — have an unfavorable opinion of Mueller than a favorable one. The remaining 32 percent don’t have an opinion or say they haven’t heard of Mueller.

This is just one poll, but it may be an unsettling sign that the president’s attacks on the special counsel, bolstered by conservative media, are having an effect, at least among Republicans. A total of 53 percent of Republicans view Mueller unfavorably, up from 27 percent in July 2017, according to Politico. Democrats’ opinions have also dipped slightly; now 24 percent see Mueller unfavorably versus 21 percent in July 2017.

The Politico/Morning Consult poll was conducted June 7 through 10 among 1,994 registered voters, and covered an array of topics, including Mueller and the special counsel investigation.

Trump largely avoided going after Mueller by name after the special counsel investigation was convened in May 2017, though he may have fumed behind the scenes. But that changed in recent months, as the president has escalated his cries of “witch hunt” and seized on conspiracies such as “Spygate” — the false allegation that the FBI planted a spy within the Trump campaign — to sow doubt and confusion about the investigation.

Mueller has indicted at least 20 people and three companies and gotten five guilty pleas since the investigation began.

But it is not all positive for Trump. The poll also found that 48 percent of registered voters believe he tried to impede or obstruct the investigation into whether his campaign had ties to Russia. That breaks down largely along party lines — 79 percent of Democrats (and 47 percent of independents) believe Trump did so, compared with just 14 percent of Republicans.

Then there’s the question of pardons. A majority of registered voters polled, 59 percent, said Trump shouldn’t pardon himself if he’s found guilty of a criminal offense as part of the Russia investigation. Trump has said he has the “absolute right“ to pardon himself, though legal scholars think it’s a bit of a constitutional gray area. It would, no matter what, be unprecedented.

Which is probably why the partisan split is a little less dramatic on this issue. Just 13 percent of Democrats say Trump should pardon himself. Meanwhile, 34 percent of Republicans support Trump pardoning himself. But the same share of Republicans — 34 percent — oppose the idea.