There is a difference between the editorial board of The Dallas Morning News, and The Dallas Morning News as a whole. The editorial board takes stances on particular issues - such as the one in favor of the rail legislation - but the news department doesn't.
The editorial board and news don't work hand-in-hand as you seem to indicate. The are two different and independent staffs.
You seem to think of the DMN as a monolithic entity, which is a basic misunderstanding of how things work.
Also, the decline of the DMN print circulation has nothing to do with any stances taken by the editorial board or any stories about the news department. Actually, news coverage is vastly more balanced now than in the first half of the century when newspapers had a much higher market penetration.
The number of readers of the DMN and many other papers are increasing, but people are reading online where ad rates are lower. The biggest cause of newspapers' financial trouble the plentiful free content on the Internet and Craig's List and other free online advertising sites.
You've obvious done research on rail and the fight in Austin. You should actually do some research on newspaper before you start commenting on that industry.