A lot is going to have to change in the natural gas market to start replacing large amounts of our coal capacity with natural gas. Our distribution networks are hugely complex, aging, and very much tied to domestic supply.
Electric utilities built most of their base load capacity (coal, nuclear, hydro) before 1980, and a lot of this (the coal/nuclear part, that is) is coming up for replacement at the same time that demand has been creeping up, eating the surplus capacity afforded. The easy way out, especially with more investor-owned utilities (IOUs lol) and fewer state-owned, is to start adding to your generating fleet by installing plants which are only used several weeks a year at very high load. These are invariably plants which are cheap to build and expensive to run (because of fuel cost per kWh). NG-fired gas turbine generators are the dominating solution.
These low investment/NG-fired capacity upgrades all have their straws in the same glass, as it happens, and are being used for more and more weeks per year. Not only that, but they're also competing against the market that was practically made for NG, heating. We've been fortunate that, so far, the big summer peak in electricity consumption from air conditioning use has been on the opposite end of the year from the big winter peak in NG heating consumption. (with regard to both NG distribution and price reasons)
However, all this extra consumption is making NG prices are nuts, and--anecdote warning--I've seen a utility go a summer without running their GTs simply because it was actually cheaper to buy off another near-overloaded utility than to run peak plants on NG, which just never happened. Those prices aren't going to get any better running NG-fired capacity not only during the summer peak, but even during the not-to-be-sneezed-at winter peak. Coal is king, and the only way we're ever going to start replacing it or adapting to its decline in affordability is with thoughtful, long-term investments in efficient base load and phasing out of "temporary" capacity upgrades. This is not just a matter of one generation method/energy source being preferable to another, it's a systemic lack of strategy in our energy sector for preparing for changes which they already know will happen or imposed.