That's neither relevant nor true.
The case, D.C. v. Heller[1], was decided 5-4 with Scalia, joined by Roberts, Kennedy, Thomas, Alito, representing the majority.
Scalia (1986) and Kennedy (1987) were nominated by President Reagan who had won the 1984 election with 58.8% of the vote (v.s. 40.6% for Mondale).
Thomas (1991) was nominated by President Bush who had won the 1988 election with 53.4% of the vote (vs. 45.6% for Dukakis).
Roberts (2005) and Alito (2005) were nominated by President Bush who had won the 2004 election with 50.7% of the vote (v.s. 48.3% for Kerry).
Not some, __all__, of the justices that decided that case were appointed by Presidents who had won both the popular vote and the electoral college.
Not that it matters though. A justice appointed by a President who only wins the electoral college is just as much as a justice.
A militia is made up of ordinary citizens. It’s armaments are those of its members. It’s not a separate body. For it to be in working order, the populace are the ones that need to be armed and their right to bear those arms must not be infringed.
Note that the militia angle is merely an additional reasoning for why those rights exist. It’s an example, not a precondition.
But then, one of the tragedies of modern America is that the Supreme Court seems to have become as much a political entity as a judicial one.