President Donald Trump campaigned on building a wall on the Southern U.S. border. A wall was not only part of his very thin platform, it was part of the first speech he made announcing he was running for president.

"I would build a great wall, and nobody builds walls better than me, believe me, and I’ll build them very inexpensively, I will build a great, great wall on our southern border. And I will have Mexico pay for that wall," he said. "Mark my words."

As time went on, even after he was elected, Trump had every opportunity to, as his supporters love to chant, "build the wall."

A Republican president had a Republican House and a Republican Senate, for two years.

How has he not managed to fulfill this campaign promise?

Why has he waited so long?

Trump waited until Thursday to decide to die on this hill. He has now forced a government shutdown, because with a Democratic-controlled house starting in two weeks, he knows the wall will be dead. It's not going to happen.

And yet, he's forcing a vote on a bill he forced border wall funding into, after promising to sign one without it – until far right wing extremist pundits, from Ann Coulter to Rush Limbaugh, to Laura Ingraham, openly criticized and mocked him for not fighting for his wall.

But why win the fight for the wall, when you can use not getting the wall to raise money?

Case in point, today:

Trump is fundraising on the wall – or, more specifically, on the issue of the wall.

Here's a Trump fundraising email, also from today:

And just nine days ago, another wall-as-fundraiser email:

If Trump actually gets his border wall funding, he loses the argument.

Trump doesn't want the wall, he wants the fight – because he wants the cash.