Go look at Wikipedia for all the NV senators since 1864 and you'll basically see that only death or extreme corruption can remove a Nevadan US senator from office once they're in. As soon as they get in, all the state industry (mining, gaming) lines up behind them forevermore. Also, Nevada voters realize that US Senators acquire favors from horse-traded votes that eventually come due to the benefit of our state -- we hope. It matters little to Nevada what we trade for, since we have nothing to give but our Capitol Hill votes, only thing that matters is what we get in return. If they lose their seat in the US Senator because they failed to be re-elected, then something really out of the ordinary occurred to make it so.
This is the reason that Nevadans weren't likely to give up a Senate Majority Leader for some brand new would-be junior Senator from the minority party, like Sharron Angle.
Basically, anyone not already representing Nevada in the US Senate is monkey meat. Dean Heller was chosen by Governor Sandoval to replace John Ensign who only resigned after losing a court battle to keep evidence out of a Senate ethics violation investigation. Had Ensign won that court battle, he'd probably still be a US Senator from NV. Sure, he probably paid his mistress with public funds to stay quiet about the affair, but in NV that probably wasn't enough to yank him out of the Senate: The reasoning being that he had ten plus years of favors up on Capitol Hill saved up for our state, and some extramarital affair alone wasn't going to change any voter's minds in our state where prostitution is legal for crying out loud.
To help prove my point about how Nevadans just don't change senators, go look at the tenure that US Senators from Nevada have served in office at the Wikipedia at the link I gave above. Notice how US Senators stay in office for 20+ years until they die. Notice how the pictures of the Senators go from Hi-Def megapixel portraits in the modern age, then to the 1970s, to black and white pics from the 1950s, to grainy Jazz-age B&W pics where the Senator is dressed like Woodrow Wilson, to grainy Daguerrotype photos of the US Senator from Nevada wearing mutton-chop sideburns like his picture was taken by Matthew Brady right after Gettysburg. See how the time passes 100+ years in only a handful of portraits?
Nevada Senators typically die holding office, or don't seek re-election because they're 92 years old and it's time to call it quits. Anything else is a rare exception.
Another thing to point out is that all of those long serving senators basically have every significant street, town, dam, bridge, airport, body of water, highway, mountain peak, and state park in this state named after them. There isn't much of anything left in the state that doesn't have a Nevadan Senator's name attached to it.
Lastly, go watch 'Godfather II' or 'Casino'. Tells you all you need to know.
Excellent commentary on NV political dynamics.