Amy Walter:

But there's definitely a very strong correlation between how people feel about the president and how they're voting. And we have seen that in some of the special elections. We have seen this in the polling in these House and Senate districts.

Listen, the president's stronger approval rating is really good for Republicans running in those very Trump-friendly states. This is where the Senate map begins to become very problematic for Democrats, in North Dakota, Missouri, Indiana. They have to hold all of those states, trying to pick up other red states, like Tennessee and Texas.

So, as the president's approval rating goes up there, harder for Democrats in the Senate races. But the numbers — this to me is the most fascinating piece of this. When I compared The Wall Street Journal poll that came out this weekend with the final poll — well, it was the exit polls — I don't want to get into the details here.

But Pew also did their own survey of the 2016 voters. When you look at where the president sits right now, he's exactly where he is with — in terms of the approval rating of him overall and with almost every single demographic group.

For example, among men in 2016, Trump won 52 percent of those vote voters. Today, he has a 56 percent approval with men. With women, he won 39 percent. He has a 38 percent approval. Now, white voters who have a college degree, 38 percent approval now, won them with 38 percent.