According to Gallup, 47% of Americans own guns. That equates to about 118,000 people in Lincoln alone. If just 1% of those people in Lincoln decide to band together and fight for their rights that's still almost 1,200 people. 1,200 determined patriots could make quite a stand, enough that no one in local or Federal government would risk the PR nightmare.
Consider also that most of the men and a large number of women in that group would have had combat training and/or experience in one or more of the wars we've been fighting in since Gulf I, and they would know weapons and tactics.
Someone mentioned guns falling off of boats in the river .... even now I have no doubt that weapons and ammo sealed in weather proof containers have been concealed at various locations around the region. And, if push comes to shove, a lot of police and active military would act for the Constitution and not against it. I think Obama believes that as well, which is why in a campaign speech in Colorado Springs in July of 2008 he called for a 250,000 "civilian defense force" that would be "just as well equipped and just as well trained as the US military". You have to ask why that would be necessary? We already have a National Guard, a professional army, and over 700,000 police active police officers around the country. I think one comparison comes to mind -- the Chinese Red Guard, a group of Marxists armed to specifically suppress any who disagree with administration policy. His "civilian defense force" would be recruited from those with a Socialist view of government. People read "Mein Kampf" and thought that Hitler wasn't serious. He was. Obama has not concealed his disregard for the 2nd Amendment and concealed carry:
http://www.stoptheaclu.com/2008/10/30/obama-audio-i-want-to-ban-concealed-weapons-permits/and he takes a politician's course in discussing gun bans. He's for it in Liberal settings and against it in Conservative settings. But regardless of what he says, it is what he does that shows he is a gun banner. Biden and Reid are exactly the same way: