The DREAM Act doesn’t affect the kids who are crossing the border right now. There’s a very specific set of guidelines for those kids. It requires having been brought here as a child, and being here for some time - not just simply arriving in the country under age 18. People in other countries do know that.
Amnesty has existed in the U.S. for people seeking it as illegal immigrants since 1986 - when it was passed under (drum roll please) Ronald Reagan.
The ones who are crossing are doing it hoping to stay under amnesty laws passed while Reagan was in office or (drum roll please) while Bush was president. It was “Hagel-Martinez Comprehensive Immigration Reform Legislation” passed in 2006 that actually “opened the floodgates” to people entering the U.S. because it allowed people to join family members already living within the U.S. Here are two discussions on that bill. The first talks about money provided to step up border protection. The second discusses the number of increased people that bill allowed to pass into the U.S.
So it isn’t the DREAM Act that’s causing all the problems. That’s a red herring, and people trying to blame the guy who’s currently in office.
Things have changed since those other laws were passed. Our own economy has gotten poorer since 2006 and that means we don’t have extra jobs to support any growing population, our government has grown contrary within itself and that means they can’t agree to make new law, and outside of America the world economy has also grown worse - and that has increased violence meaning more people are validly seeking asylum under the 1986 U.S. asylum rules.
An attempt was made to streamline the process of incoming interviews with teens to see if they really met asylum standards, or could simply be sent back across the border, but no one could agree in Congress.
The people sending their children here are doing so out of desperation, because they’re watching people die and don’t want them dead. That is your better explanation.