THE CASCADING INVESTIGATIONS into relationships between Russia and Donald Trump’s campaign and staff rings loudly with echoes of Watergate. Trump sometimes seems to invite the parallel, tweeting about taping White House meetings, and inviting reporters into an unannounced meeting with Henry Kissinger, Nixon’s secretary of state. “We’ve seen this movie before. It’s reaching Watergate size and scale,” said Republican Sen. John McCain.

Trump may have an advantage over Nixon in one sense. Nixon began Watergate from a stronger position in terms of public opinion than Trump enjoys now, but he also lived in a time of less polarization, where even his supporters were less loyal than Trump’s. Put another way, our politics are so polarized that Trump’s supporters may be too loyal to allow his approval rating to sink to Nixonian depths.

One thing to look for is when the loyalty of Trump’s base no longer outweighs the constant negative attention Trump seems to invite. And that’s where the question remains of just how loyal and how large his base is.

The Senate Watergate hearings began on May 18, 1973, 44 years ago to the day. Nixon, who’d won reelection in a landslide, had been dinged by the Watergate news but still had a 48 percent approval rating on the eve of the hearings. A few weeks later, in June, Gallup found only 19 percent of Americans thought Nixon should be impeached and forced to resign.

The hearings took their toll over the summer. By the fall of 1973, the trendlines for these two measures crossed: more Americans favored impeachment and removal than approved of the job Nixon was doing. In January 1974, Nixon’s job approval hit 23 percent. It remained there, more or less, until August, when Nixon resigned with a 24 percent approval rating. Still, as unpopular as Nixon was, Americans were reluctant to remove him. It wasn’t until right before Nixon resigned that a majority (57 percent) favored his impeachment and ouster.

If Nixon were staring down at his scandal, Trump is looking up at his from a deep hole. As of May 16, Gallup’s three-day tracking poll puts his job approval at 38 percent; 57 percent of American disapprove of his job performance. That figure does not fully reflect the impact of the Comey memo or Trump’s reported sharing of intelligence with Russians in the Oval Office. FiveThirtyEight and Huffpollster’s are a couple points better, but neither reflect the latest news developments.

Polling on a Trump impeachment is very limited, so it’s hard to draw a direct comparison to similar trend lines on Nixon. As more lawmakers discuss the prospect publicly, pollsters will likely take note and begin asking the question more regularly. The left-leaning Public Policy Polling asked the question in a survey released this week. The firm found 48 percent in favor of impeaching Trump and 41 percent opposed. Question order is important, and the impeachment question was one of the last in the survey. This can prime respondents to answer a certain way by getting them thinking about negative aspects of Trump’s presidency first. Even so, the tilt toward impeachment is likely not a good sign for Trump.

Although Trump’s polling has been historically weak, he may not reach the depths of disapproval that Nixon plumbed. American politics has become vastly more polarized over the past 40 years, the blocks of partisans on either end of the spectrum seem all but immovable. Trump said, during the campaign, that he could shoot someone on 5th Avenue and not lose support. Among a certain block of voters, he may well be right. If that block is large enough, Trump may not reach Nixonian lows, even if voters looking for impeachment get their way.

That’s at least partly due to upheaval in the media environment in the decades since Watergate. In the ‘70s, Americans got their news from the same three broadcast networks and local and national print press. However voters chose to interpret it, the information they received was more or less consistent. Today, the media landscape is fractured and siloed; Trump voters watching and clicking on only their preferred outlets are getting a very different view of events than those watching other sources.

The hyper-partisan dynamic seeps into Congress as well, with its mostly safe Democratic and Republican districts. For more members, their district is safe enough that a primary challenge is their main concern. Investigating or impeaching a Republican president will not improve their electoral prospects. Ultimately, it was Republicans in Congress who turned on Nixon, voting for articles of impeachment and forcing his resignation.

But even the most reluctant Congressional Republicans will respond if their base voters begin to waver. Will they? So far, the polling is mixed. The Washington Post’s Philip Bump points out three-quarters of Republicans support the Comey firing, and a majority of them accepted the administration’s initial explanation that it was because of Comey’s handling of the Clinton email investigation. But Amy Walter of the Cook Political Report notes that several polls have shown a drop-off in strong support for Trump among Republicans, even as his overall support numbers with GOP voters have held steady. Morning Consult finds Trump continuing to bleed strong support among his own voters.

That trend, combined with a surge in strong disapproval of Trump among Democrats, could spell trouble in the 2018 midterm elections. Republicans will be looking closely at special elections in Montana and Georgia to gauge the political fallout. In March 1974, a GOP loss in an Ohio special election helped spur GOP defections from Nixon. A Republicans loss in either or both of the upcoming elections could have a similar effect.

With new developments coming multiple times a day, it’s hard for pollsters to get a full sample between political shockwaves. But new polling to come will show whether Republicans are starting to break from Trump. Even if some do, the hardened partisan structure of American politics suggests Trump’s floor may end up being somewhere above Nixon’s 24 percent. If that proves to be the case, it could say more about our current political culture than about the two men and their deeds.

Richard Parr is the research director and Steve Koczela is the president at the MassINC Polling Group.