Friday’s news that the Justice Department had indicted 12 Russian agents in connection with interference in the 2016 U.S. elections was a major development in the fast-moving Robert Mueller investigation. But that doesn’t mean it will change anyone’s mind in the long run.

Since Mueller was appointed special counsel in May 2017, his investigation has brought charges against 35 people or businesses, including former Trump confidants Paul Manafort and Michael Flynn in late 2017. But while American opinion about Russian involvement in the 2016 election has shifted over that time, the shift hasn’t always been lasting.

In late February 2018 — just after Mueller indicted 13 Russians and three companies, accusing them of trying to influence the 2016 election by stirring up anti-Clinton and pro-Trump sentiment online — Quinnipiac University asked poll respondents whether they thought the Russian government tried to influence the 2016 presidential election. Seventy-six percent said “yes,” while 18 percent said “no.” One month earlier, however, only 68 percent had said “yes,” while 27 percent had said “no.” Although we can’t know for sure, it’s reasonable to theorize that the indictments played a role in that increase.

CNN also asked Americans about the Mueller investigation immediately after the February indictments. In that survey, 61 percent of respondents said Russian election meddling is “a serious matter that should be fully investigated”; 34 percent said “it’s mainly an effort to discredit Donald Trump’s presidency.” That also represented a slight uptick from the previous month’s results: In January, 58 percent said it was a serious matter, and 38 percent said it was an effort to discredit Trump.

But in March, the next CNN poll threw a curveball: The figures dropped back down and have stayed at those levels ever since: The most recent poll, taken in June, showed a 55-percent-to-35-percent split.

Finally, a pair of Fox News polls lend credence to the theory that Americans’ views on Russian interference remain steady in the long run. In June 2018, 56 percent of Americans told Fox News that they thought Russia interfered in the 2016 election, while 34 percent did not think so. That was virtually identical to Fox News’s findings in a July 2017 poll, in which 55 percent of respondents said they thought Russia interfered and 34 percent said they did not.

The moral of the story? As ever, don’t underestimate the intractability of people who have dug into their partisan trenches. In the three aforementioned polls, Democrats almost uniformly believed that Russia either interfered in the election or that Russian interference was a serious matter, while Republicans were more divided. A potential explanation is easy enough to find: Even though Trump has softened his stance this year, he previously repeatedly suggested that Russia had not attempted to influence the election. That and his denigration of the Mueller investigation may contribute to Republicans’ skepticism of Russian involvement.

The 2016 election is in the past, though — what about 2018? The June poll from Fox News asked whether Americans were worried about Russian attempts to influence the 2018 midterm elections and found that 22 percent were “extremely” concerned, 12 percent were “very” concerned, 26 percent were “somewhat” concerned and 36 percent were “not at all” concerned. A CBS News poll from March 2018 found similar numbers. These polls also showed wide partisan splits, but they also suggested the possibility for change. For example, in the Fox News poll, 24 percent of Trump voters (the same as the share of Trump voters who said they believed Russia attempted to interfere) said they were “somewhat” worried about 2018 meddling; maybe these voters will raise their level of concern to “very” or “extremely” as they watch the Mueller investigation unfold. And only 40 percent of Clinton voters told Fox News that they were the maximum level of worried. With 16 weeks left until the midterm elections, there’s plenty of time for anxieties to mount.

Check out all the polls we’ve been collecting ahead of the 2018 midterms.