i've never seen a plastic gun, please Mr. Heller, i would like you to show me an example of your so-called "plastic gun"
but you have to think: people like heller have no common sense, especially with guns.
I believe that some here are confused regarding the who's-who in this case.
Heller is a security guard that lives in the District of Columbia. He (and some other original plaintiffs) attempted to obtain permits to keep handguns in the District. He (and the others) were summarily denied permits and, in response, sued the District for relief. In the original case
Parker (et.al) vs. District of Columbia, the district court found in favor of the plaintiffs (one of which is Heller) and overturned the District's handgun ban.
The District was unhappy with this decision and appealed the ruling of the district court to the US Supreme Court. Due to some procedural issues, other plaintiffs were determined not to have standing in the appeal, so the appellate case became
District of Columbia vs. Heller. Time will tell how the USSC rules.
In short: Heller is on 'our' side.
While I'm not exactly thrilled with the way that Heller's attorney handled the questioning, it is very plausible that he (intelligently) made concessions on issues that are not specifically relevant to the ruling on this case. By making these concessions, it effectively takes them 'off the table' and no longer an argument in the context of this case. Since the real question addressed in this case is: "Does an individual have a right to keep a handgun in the District of Columbia?," the 'acceptableness' of machine guns and non-existent plastic guns is moot. The decision in this case will answer the question at hand, without addressing the context of machine guns.
This case, if decided in favor of the pro-gun argument, however can be used as precedent later. If it is determined that it is unconstitutional to ban/restrict a specific type of firearm (in this case, handguns) then it is by extension unconstitutional to restrict other types (such as machine guns). However, this question is for another case.