CNN  — 

President Donald Trump is staring down possible impeachment. Fortunately for him, his base of very conservative Republicans in the Senate likely would save him from being removed from office.

But CNN/SSRS polling in September suggests that Trump should be more worried about a part of the Republican Party that gets less notoriety: the more moderate part. This part of the party won’t play a large role in impeachment proceedings, but their feelings toward impeachment and Trump in general could hurt his re-election bid.

The yearning for impeachment and removing Trump from office has risen significantly among moderate and liberal potential Republicans (i.e. Republicans and Republican leaning independents). Nearly a third of moderate/liberal potential Republicans in our latest CNN poll said they wanted Trump impeached and removed last week, while about two-thirds didn’t want that. Back in late May, the split was 16% for impeachment and removal and 81% against it. This is statistically significant movement.

The seeming shift of this moderate/liberal potential Republican bloc shouldn’t be too surprising, given what a different CNN poll found in early September. In that poll, 25% of moderate/liberal potential Republicans disapproved of the job Trump was doing as president. Only 69% approved. Trump’s job approval ratings with this moderate/liberal Republican bloc looks like the percentage who want him impeached and removed from office.

Now compare what’s going on with the very conservative part of the Republican Party. Among those who are very conservative and can be classified as potential Republicans, Trump remains a very popular president. His approval rating in CNN’s early September poll among very conservative potential Republicans was 94%, about 25 points higher than his rating with the moderate to liberal wing of the party.

Obviously, you shouldn’t expect moderate and liberal Republicans to be as behind the President as very conservative Republicans. Those toward the center of the ideological spectrum are more likely to go against their party.

Still, this is an underperformance for Trump.

For perspective, 85% of moderate/conservative potential Democrats and 98% of very liberal potential Democrats disapproved of the job Trump was doing in our early September CNN poll. This is a 13-point gap going from left to right within the party. On the Republican side, the gap is about double that from left to right within the party.

Not surprisingly, very conservative potential Republicans have been far less likely to back impeachment than moderate/liberal potential Republicans. The trendline on impeachment is much different among very conservative potential Republicans and moderate/liberal potential Republicans as well. Back in May, 2% of them wanted Trump impeached and removed from office. Today, it’s 1% of this bloc who want Trump impeached and removed from office.

In other words, Trump’s base is intact and isn’t really moving. The loudest part of his party is going to have his back – and it’s a group that now makes up a lot more of congressional Republicans than it used to. This is why the chance of Trump getting removed from office is minimal, and it may make Trump believe he can count on more Republicans in his re-election bid than he actually can.

The problem for the President is that in the actual electorate, moderate and liberal potential Republicans make up about the same 25%-30% of potential Republicans as very conservatives do. (The other about 40% of the party is made up of somewhat conservative voters.)

When you dig deeper into the crosstabs, you see moderate and liberal Republicans may even have more power than the national polls indicate. In a combined sample of Michigan, Pennsylvania and Wisconsin Republicans in the 2018 midterm exit polls, about 40% call themselves either moderate or liberal. These, of course, were the big states that flipped the electoral college in 2016.

Now, I don’t want to overplay the role of a group of voters who make up, at most, a third of the Republican Party. But when you look at the math, something’s going to have to give for Trump: Either he’s going to need to win a significantly larger chunk of moderate/liberal Republicans than these numbers suggest he’s capable of winning, or the Democratic candidate will have to underperform among Democrats.

Because unless something happens, it’s difficult to imagine Trump winning when only a little more than two-thirds of moderate/liberal potential Republicans approve of the job he’s doing in office and nearly a third want him impeached and removed from office.