Yes.
Mexico has been a democracy where the citizens can elect a president and representatives since 2000.
We the people
no
Citizens elect the members of the Diet.
the citizens elect them
A Republic .
If you meant 'what form' - it's a democratic government.
president
constituents
a government in which the citizens elect their leaders
A democracy is a political system in which the supreme power lies in a body of citizens who can elect people to represent them.
direct democracy, republic