Irresponsible politicians are the new face of the "Grand Old Party." This means that the voting public are less likely to trust the candidates that the GOP are putting forth. This lack of confidence certainly smears the GOP and means that they will be less likely to win political contests.
The media is to blame because the political parties simply respond to the mood of the country. The mood of the country is affected by the mass media. The political parties like the GOP try to not to step on anyone's toes yet at times that is the worst decision they can make.
The Republican party is not responsible for anyone's confidence issues but its own. Perhaps modern politicians do not have confidence because they know/believe the elections are rigged. Perhaps they lack confidence because they know that their intentions are dishonorable. Alternatively, maybe their confidence is low because they know that will lose even if they win. The nation is a hot mess that is too much for anyone's plate.
Americans see both major parties as untrustworthy. Lack of confidence in our government has declined fairly steadily since the 1970s. Politicians are perceived as selfish and out of touch with their constituents, no matter what party they represent. The American people are frustrated with the inability of the major parties to agree on important issues, such as healthcare. Neither party can be solely blamed for the gridlock.