All democratic Constitutions explicitly states or imply that the power belongs to the people. They also state that the people delegate their power to some representatives which temporarily rule the country in their behalf. People's temporary representatives are choosen by means of elections.
Democratic control is the monitoring and checking that the people exercise over their representatives and institutions to verify how they get and use the power. Without democratic control democracy may easily degenerate into oligarchy or dictatorship. All citizens MUST be allowed to exercise their democratic control over public institutions, therefore such right can't rely on any specific knowledge or competence.
Democratic control of elections is extremely important because elections are the very heart of any Democracy.
no democratic control is possible over electronic election because e-votes are invisible and electronic procedures unverifible to humans.
As an example of a very strong democratic control over elections, please have a look at the italian paper elctions' procedure