CNN —  

President Donald Trump is taking his case to the American people over why they should back him in the partial government shutdown.

His primetime address on Tuesday will be about the “Humanitarian and National Security crisis on our Southern Border,” he tweeted. But Trump is facing an uphill climb: polls show a majority of Americans blame him and Republicans for the shutdowns, and the majority have also consistently been opposed to his idea of a border wall with Mexico.

The average of polls taken since the shutdown began indicate that Americans are blaming Republicans for the shutdown. In the average, about 50% think Trump is most to blame, 35% think congressional Democrats are most to blame and about 5% think congressional Republicans are most to blame.

When you combine all the numbers together, about 55% blame Republicans (either Trump or congressional Republicans) and about just 35% blame Democrats for the shutdown.

The good news for Trump and Republicans is that it is not clear their position on the shutdown is any worse than it was before it began. Polls before the shutdown started indicated that Americans would blame Republicans for a shutdown by about a 15 to 20 point margin, which is about where the polls are now.

Trump and congressional Republicans’ steady position is in large part because they continue to hold onto their base. In the average of polls, more than 80% of those who voted for Trump in 2016 say congressional Democrats are more to blame for the shutdown.

There is perhaps some sign, however, that Trump may be losing voters in the center of the electorate because of the shutdown. Before the shutdown began, Trump’s position on the shutdown was somewhat more unpopular than Trump’s overall approval rating.

Now, the President’s approval rating seems to have taken a bit of a dip in the last few weeks as the shutdown has taken its course. According to the FiveThirtyEight aggregate of polls, Trump’s approval rating stands at just 41%. That’s the lowest it’s been since September by a point. His disapproval rating, meanwhile, stands at 54%, which is the highest by a point it has been since September.

Interestingly, Trump’s not doing considerably better with voters. As I’ve written about previously, Trump’s secret political weapon is that his base is older Americans and they “are more likely to be voters than younger people are.” The latest average of polls has his approval rating with voters at only 42%. That’s Trump’s worst standing since September. His disapproval is 53%. Like his overall disapproval rating, this is Trump’s highest since September.

The fact that Trump is losing the shutdown fight in the court of public opinion shouldn’t be a surprise. He came into the negotiations in a rather weak position.

Trump’s biggest issue is that he wants funding of a US-Mexico border wall. While that may be popular with his base, Americans have been consistently opposed to a border wall. Before the shutdown, they opposed it by about a 10-to-20 point margin. There’s no sign that’s changed in the latest polling.

His second and smaller problem is that he is less popular than his main adversary, House Speaker Nancy Pelosi. That’s quite a feat given that congressional leaders (by virtue of leading an unpopular branch of government) are usually unpopular. This hurts his ability to potentially win the shutdown by making it a popularity contest between two politicians.

Of course, for a President who has been satisfied with being popular only among his base, Trump having only the support of Republicans may be all he needs to not give into Democrats during this shutdown. On the other hand, Democrats have no reason to give into Trump with the public on their side.

The result could be an extended shutdown.