And, while our lackluster Congress may be gridlocked, ineffective, and even irresponsible on many issues, they never tolerate an invasion of their prerogatives, i.e., their turf, by the executive branch of government. Not only that, these kind of jurisdictional conflicts are usually not governed or determined by party politics: Just the opposite—they typically unite congressional Republicans and Democrats, albeit briefly, and if only to deal with such power grabs by the president.
So, is it possible that some Democrats in Congress would oppose the whole idea of executive orders on gun control? Yes, it's not only possible, but also highly probable. The common denominator in all of this is that the Congress will be the primary mover on substantive gun control regulation, if there is any. And, even this minimalist approach comes with the very real political risk that voters will react again just as they did in 1994, and "take it out on the Democrats" at the next available election opportunity.
The bottom line on executive orders is very simple: Don't hold your breath. Does even the suggestion or the threat of executive orders set up a jurisdictional conflict with the Congress? Yes, and it could even motivate Congress to "do something" on gun control, but they would never admit it. What exactly? Again, don't expect a lot, and primarily because of the harsh political lessons of the 1994 voter backlash, when Democrats lost the majority they held in the House for 40 years, and directly because of the "assault weapons ban".
Now, for the New York governor (and also the New York City mayor) and their penchant for emotional antigun political rhetoric. This kind of stuff—especially in the overall context of such things—is much ado about nothing, mostly for the following reasons:
What's the bottom line? Like the insightful quote from Cool Hand Luke—"What we've got here is [a] failure to communicate." And, while there will probably be both state and federal action as a result of Sandy Hook, hopefully it will focus on the primary cause of these kinds of tragedies—our failed/non-existent/broken mental health "system." To the extent that the tragedy may also serve as political will for more substantive gun control, cooler heads will eventually prevail—they usually do. And, perhaps most important, our forefathers intended that our limited form of government work exactly that way.