Over the last 97 years since Daylight Saving Time was first introduced in the U.S. in 1918 there have been several attempts to keep all of the U.S. following Daylight Saving Time within their respective time zones. Most recently the period of Daylight Saving Time was increased due to The Energy Policy Act of 2005.
Benefits of staying on Daylight Saving Time throughout the year include daylight longer during evening hours, not having to adjust clocks, timers and other timing devices twice a year and a decrease in work related accidents that result from time change disrupting established sleep schedules.
For additional information about the benefits of remaining on permanent daylight saving time please search "Daylight Saving Time In The United States" in Wikipedia.