What factor gives citizens' groups influence over legislators on environmental issues

Their leaders can run for office.

Explanation:

Citizens' groups can choose a leader who takes the ideas of the group to the legislators. it is necessary for the leader to have a certain influence among the legislators and to be able to put the opinions of the citizens' group as a forum for discussion among legislators. For the leader of the group of citizens to be able to do this, this leader must compete for the position of legislator. In this way, the leader is able to take the claims of the citizens to the legislators and make these claims heard and discussed.

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .