chicago democrats pennsylvania congressional delegation send letter federal rail regulator monday raise concern possible negative impact merger canadian pacific norfolk southern corp. letter send surface transportation board raise concern impact could railroad job pennsylvania say merger could lead disinvestment rail infrastructure state senator bob casey five members u.s. house representatives democrats also write deeply concern vote trust structure canadian pacific propose bid u.s. railroad canadian company mid-november disclose 28 billion offer buy norfolk virginia-based railroad norfolk southern reject canadian pacific advance set stage possible proxy battle surface transportation board would review merger two railroad would test case since regulator rewrite rule approve takeovers 2001. review process would include public hear rail customers labor group elect officials would allow weigh letter pennsylvania democrats write believe acquisition could hurt thousands rail shippers manufacturers local communities well rail workers state urge thorough review propose merger canadian pacific say takeover norfolk southern would lead 1.8 billion annual save early january two senior democrats u.s. house representatives urge board reject merger canadian pacific norfolk southern number industry group rail customers plus couple unions represent workers norfolk southern also come merger last week board post letter rail customers argue contrary merger canadian pacific norfolk southern would create transcontinental railroad would result good service pennsylvania democrats raise concern cp 's norfolk southern bid