Public opinion on the Russia investigation has been pretty stable all year — Republicans are skeptical but Americans overall support it. It’s hard, therefore, to see the much-hyped “Nunes memo,” which Trump declassified and congressional Republicans then made public on Friday, changing all that much.

Trump has reportedly told friends he thinks the document — which was written by Republicans on the House Intelligence Committee, led by California’s Devin Nunes, and criticizes the FBI’s conduct in the early stages of the Russia investigation — will undermine special counsel Robert Mueller’s probe, but opinion on Trump, Mueller and Russia largely falls along partisan lines, which will make it hard to move. And where it doesn’t, Trump comes out the worse. So Trump should be careful about taking any action based on the memo, like firing Mueller — at least if he wants to avoid a public backlash.

The broader public has demonstrated continued faith in the Russia investigation.

CNN has asked respondents for their views on the Russia investigation four times since August. Each time, between 58 and 64 percent of respondents said that they believed the Russia investigation was “a serious matter that should be fully investigated.” In contrast, between 32 and 38 percent of respondents said the investigation was “mainly an effort to discredit Donald Trump’s presidency.”

A lot about the Russia investigation has changed since August — most significantly with the charges being brought against four people who worked on Trump’s campaign. Yet during that time there was virtually no change in attitudes toward the probe.

Moreover, most people appear to think the investigation is fair. An Associated Press poll from December found that 57 percent of Americans trusted that Mueller was running a “fair and impartial investigation,” compared to 42 percent of Americans who did not. A recent Washington Post-ABC News poll found that 50 percent of Americans approve of the way Mueller is running the Russia investigation, compared to only 31 percent who disapproved.

Who thinks the Russia investigation is an effort mainly to discredit Trump? Republicans.

There is a sizable share of Americans who are skeptical of the Russia investigation, but they’re mostly GOP partisans. According to CNN’s January poll, 77 percent of people who said they approve of Trump’s performance as president, as well as 75 percent of self-identified Republicans, said they thought the investigation was mainly aimed at discrediting Trump. (Those two groups overlap, of course.) A plurality of Republicans (49 percent) disapproved of the way Mueller is running the Russia investigation, according to a recent Washington Post/ABC News poll. That number has changed little since November.

Meanwhile, in an Economist/YouGov survey conducted in late January, 34 percent of people said the “deep state,” the term Trump and his allies use to refer to officials in the federal government opposed to his initiatives, is trying to “overthrow” Trump, while the rest of the respondents said they disagreed with that statement or were not sure.

This pattern — a clear majority of Americans take the anti-Trump position, but between 35 and 40 percent of Americans have a pro-Trump view — should sound familiar. It roughly tracks with Trump’s approval and disapproval ratings. The data so far suggests that Americans are viewing the Russian investigation largely through their views of Trump overall. There are questions about the Russia investigation where Americans break from partisan allegiances, but where they do it’s largely to Trump’s detriment.

Case in point …

The public strongly opposes Trump firing Mueller and would prefer the president testify in the investigation.

In the most recent CNN survey, 78 percent of Americans overall said that Trump should testify, including a clear majority of both those who approve of his performance as president and self-described Republicans. A CBS poll last month found that 84 percent of Americans said Trump should talk to Mueller if asked, including 73 percent of Republicans.

According to the Economist/YouGov survey, just 14 percent of Americans thought Trump should fire Mueller, while 48 percent opposed that idea, with the rest of the respondents not sure. In a CBS News survey, 73 percent of respondents, including 56 percent of Republicans, said Trump should allow the Russian investigation to continue, as opposed to taking steps to end it.

A plurality of Americans think Trump did something wrong on the Russia issue.

The Washington Post-ABC News poll found that about 50 percent of Americans think Trump campaign officials colluded with Russia. Unsurprisingly, Democrats overwhelmingly say yes (83 percent), Republicans no (79 percent) and independents yes but by a narrower margin (48 percent to 40 percent). In the CBS survey, 63 percent of Americans said that Trump officials had improper dealings with Russian officials before he entered office. Asked if Trump had tried to impede the Russian investigation, 35 percent of Americans said no, per the AP poll, while 63 percent said yes.

If the goal of the Nunes memo, combined with the other tactics of the Trump administration and its defenders, is to raise doubts about the Mueller investigation among Republican voters, that mission has been accomplished. (Or maybe Republican voters were always going to be skeptical of the probe, because it was an investigation of a GOP president.)

These numbers are good for Trump if his goal is merely to avoid being impeached and removed from office by a GOP-controlled Congress. Republican voters are skeptical of the investigation and that will matter to GOP congressmen. But if Trump wants to end the Russia investigation, that will be harder. These efforts to question Mueller and his investigation do not appear to be resonating with the broader electorate.