The difference you allude to is mostly talking points, and I'll explain what I mean by that.
This new gas boom, like all energy booms that are driven by the capitalist system can only succeed as a boom. That means that it is ALL IN, language that circulated within the industry early on. All in on exploring, acquiring, drilling, pipeline building, mid-steam infrastructure building, and of course removal of all regulatory restrains, and the development of as many immediate markets as possible.
As long as gas - the resource, the industry, and the markets - remain in the private sector the notion of gas as a bridge fuel is just empty words meant to protect the private gas industry. Like coal, gas is worth nothing (in this capitalist system) until it is sold, and to investors wagering on one corporate entity or another that means their investment vehicle selling as much of it as quickly as they can, for the highest price possible in as many markets as possible.
The only hope that gas could be a bridge fuel is if we were to nationalize it - take it out of the private sector, and develop it at a measured pace that would assure US energy security for many decades to come. That of course is not going to happen, and what will happen - in my opinion - is that this resource, like US oil before it, will be produced and sold as quickly as possible to as many markets as possible, and in much too short a time we will again be a major energy importer. All the promises coming from the gas industry are a lie and a cheat, a scam.
No-one, not HRC, not Sanders, and certainly not Trump would have the audacity, let alone the political support to nationalize our natural gas endowment. Hell, the "Commonwealth" of Pennsylvania doesn't even levy an excise tax on it, as you well know. And the state legislators of Pa's neighbors are constantly huddled to determine just how low they can make their excise taxes while we turn our states into sacrifice zones.
I found a study prepared by the National Energy Technology Lab of the DOE, released in 2014, and hence done under the direction of a Democratic administration titled Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States. Find it and read it, it isn't that lengthy. In the interest of brevity I'll just say that the stated conclusion reached there was that exported LNG from fracked Marcellus gas (the example used for their study) to Europe (Rotterdam) and China (Shanghai) would not represent an increase in GHG emissions compared to coal produced in those destination regions (and all used to generate electricity.) There was one glaring dodgy assumption in the study (they "assumed" that the generation facilities would be very close to the import terminals, an illogical and unsupportable assumption.) There may be other faults in the study as well; I'm not qualified to judge whether the figures for the GHG emissions at the well-head are realistic - as reported here over the past years, several independent studies suggest that emissions and contamination of many types are under-reported and downplayed by the industry. But the gist of the report was to give the green light to exporting US fracked gas converted to LNG as far and wide as possible.
Yeah, natural gas, a Bridge of Sighs to more profits, and fuck everything else. To put a fine point on it, the study concluded no increase in GHG emissions (compared to coal for pity's sake) not a decrease, which is of course what is sorely needed.