You and a companion could drive the more than 200 miles from the Dallas-Fort Worth area to Houston and argue the entire trip about whether a high-speed rail line should be built between those two huge metro areas.You might argue about whether such a line would make money, whether for the next few decades people would be willing to pay the cost to take that ride at 200 mph or more.No one is sure exactly what that cost would be, but the best guess by experts is about 80 percent of the cost of an airline ticket. So, for a quick one-way trip, you’re talking about more than $100.OK, so some people would and some wouldn’t.What you absolutely should not argue about is where the high-speed line should begin and end. You’d want it to be close to as many potential customers as possible, especially those with higher incomes who could afford to pay. Right?So, why is it even under consideration to put the Dallas-Fort Worth terminus in southeast Dallas? Why would it be anywhere but Dallas/Fort Worth Airport, where billions of dollars and decades of work have been spent to create a transportation hub for the Metroplex?The southeast Dallas idea is completely ridiculous, yet one company that’s considering building the line is apparently seriously considering it. What that company therefore must not be serious about is serving as many people in Dallas-Fort Worth as it can.Officials of Texas Central High Speed Railway Llc., which is studying the line in collaboration with Central Japan Railway, have said they are seeking investors willing to put up as much as $10 billion to build the line without seeking any government money.Apparently, the draw in southeast Dallas is that there is a lot of land to be developed there. If Texas Central and its investors could control that development also, their profit potential could go way up.Well, if it’s their money, they can build it the way they want to. Right?Why is that necessarily so? After all, Fort Worth and Dallas both have a lot at stake here. Texas Central officials have said they believe people will drive to southeast Dallas to catch the train. But why should they have to when they’ve invested a lot themselves in building up the airport to serve the entire region?For years, an advocacy group called Texas High Speed Rail & Transportation Corp. has pushed the idea of a high-speed line to DFW Airport. The numbers are there to show the benefit, says Tarrant County Commissioner Gary Fickes, the group’s chairman.More than 4.1 million people live within 20 miles of DFW, Fickes says. They have a median household income of $84,105.The comparable numbers for southeast Dallas are 2.4 million people within 20 miles, with a median household income of $66,637.Fickes and his group say a high-speed rail line from Houston could feasibly be constructed in the Texas 360 median from south of Arlington to DFW.Want to talk development potential? DFW has approximately 5,200 acres available for commercial development. And it gets millions of visitors every year.If high-speed rail is a worthwhile venture, it could help bring hundreds more jobs to DFW.Those jobs would be accessible to everyone in the Metroplex.It’s best to see that we all have a stake in the idea of high-speed rail. If a Dallas-Fort Worth to Houston line is feasible, then DFW is where it should go.Tarrant County officials should unite behind Fickes and his argument. The rest of the Metroplex should see the wisdom of that argument, too.