You realize that each Senator has his own constituents that he/ she must remain loyal to as well, correct? If they want to hold up nominations until they hear answers from the Administration about Benghazi, then they are well within their rights to do so.
No, they're not. The Senate's confirmation role was never intended as a political litmus test. They're job is to determine whether someone is qualified, not to hold them up because a senator or their constituents don't like the nominee's politics.
Things have definitely gotten worse since Obama took office. But that's because Republicans are more spiteful than Democrats. They're not really conservative, they're just mean. No less a conservative icon than Henry Fairlie once described them as the "booboisie," and described them thusly: "Narrow minded, book banning, truth censoring, mean spirited; ungenerous, envious, intolerant, afraid; chicken, bullying; trivially moral, falsely patriotic; family cheapening, flag cheapening, God cheapening; the common man, shallow, small, sanctimonious." That was in 1980; it's only gotten worse since then.
And so here we are, in the so-called "greatest democracy in the world," and our choices boil down to two, Republicans or Democrats — evil or incompetent. Nice, huh?