Liz Cheney abruptly ended her challenge to Sen. Mike Enzi (R-Wyo.) Sunday night, citing family health issues as her reason for bowing out. While those health issues sped up Cheney's decision to leave the race, it had become clear over the last few months that her challenge to Enzi was at a dead stop due to a single issue:  She simply couldn't explain why she was running.

Liz Cheney abruptly ended her bid for the Senate Monday, but don't assume her campaign taught us anything about the state of the Republican Party. (The Washington Post)

Cheney offered any number of reasons for entering the race.

There was the "not conservative enough" argument. "We've got to stand and fight, and we have to defend what we believe in. We have to not be afraid of being called obstructionists," she said.

And the generational case. "I am running because I believe it is necessary for a new generation of leaders to step up to the plate," she said.

And, of course, the attitude argument: "It isn't good enough to say 'I tried.' It isn't good enough to say you are working behind the scene. We need a senator who is going to actively and aggressively push back."

There were two problems with Cheney's approach. First, when you are making (at least) three arguments to explain why you are running, it amounts to a giant mish-mosh for voters. Remember that the first task when you are challenging an incumbent is convincing voters that they should fire someone they have voted for before. To do that, you need a very clear argument. (Notice we said "argument," not "arguments.")  When Richard Mourdock beat Indiana Sen. Dick Lugar in 2012, it was because he made a simple case: Lugar doesn't represent your conservative values. Fits on a bumper sticker or, more importantly, in a 30-second TV ad. Cheney never settled on that single line that encapsulated why Enzi needed to go.

And that leads us to the second problem for Cheney: None of the arguments she made for why Enzi should be fired rang true. Enzi not conservative enough? In 2012, he was the eighth most conservative senator, according to National Journal vote ratings. (Liz Cheney argued that Enzi's membership in the "Gang of Six," a group that negotiated unsuccessfully on a health-care compromise, was evidence of his moderate tendencies. Of course, hardly anyone outside the Beltway -- and not many people inside it -- know what the "Gang of Six" is or did.)

Enzi too old? That's always a delicate argument to make, since it bumps closely up against the "he can't do the job anymore" insinuation. Plus, Enzi is 69 years old, which is positively middle-aged in the Senate. (Liz Cheney is 47.)

And, as for Enzi's approach not being aggressive enough? This is Wyoming -- not New Jersey.  Pot-stirrers are not necessarily what people in Wyoming want out of a senator. Enzi's low-key approach seems to be a nice fit for the state.

Add it all up and you understand why Cheney's candidacy was going nowhere. And, for those who point to all the money she raised -- more than $1 million in her first three months of cash collecting -- we would note that money doesn't buy you a message that works with voters.

The truth of the matter is that Cheney was running against Enzi because she wanted to get into elected office and she saw an Enzi primary challenge as the best avenue to make that happen. But, ambition is not a message.

Cheney's candidacy ended on an abrupt note this weekend. But the writing had been on the wall for some time: She simply never found a reason for running.