Answer: lack of access
Explanation:
If they use the mobile phones there are high chances that they won't get everyone through the phone , they may be shortage of responses or insufficient data collection due to the fact that not everyone would answer to this pollsters and they may not even have access to enough mobile phones.
The Colorado River and its tributaries provide water to nearly 40 million people for municipal use, supply water to irrigate nearly 5.5 million acres of land, and is the lifeblood for at least 22 federally recognized tribes, 7 National Wildlife Refuges, 4 National Recreation Areas, and 11 National Parks.
All of these are sources of authority
To establish some basic policies they may want to address if elected. The platforms may be selling points to some individuals and interest groups.