Okay kiddo, so imagine there are two big team of people called the Democrats and the Republicans. Both teams want to win and be in charge of making the rules in the country.
Now, some places in the country have more people who support the Democrats, and other places have more people who support the Republicans. The places that have more Democrats are called “blue” states, because Democrats usually use blue as their color.
The “blue wall” refers to four big states in particular – Pennsylvania, Michigan, Wisconsin, and Minnesota – that have historically been blue and have a lot of votes. In the past, Democrats have been pretty sure that they would win these states in elections and get a lot of votes that way. But in the most recent election, some people were surprised because the Republican team won in all of those states.
So, people talk about the “blue wall” because it’s like a wall of support for the Democrats. But if the Republicans are able to win in those states, it’s like breaking through the wall – which is a big deal in politics!