The country's presidential elections are ruled by the dollars in the campaign funds and the support of major political parties. It should not be this way.
The whitehouse.gov site should have a list of each presidential candidate with some information that they prepared. It should allow them to create opinion polls for which the results could be viewed on a national or a state by state level. It should allow them to receive, read and reply to messages. The candidate should be able to post files (video/audio/images) as well.
Administrators could put warning message popups in place before anything indecent opens.
Threats against candidates should be investigated as a potential threat to national security. A candidate should not be forced out of the election by threats.