John Piper proves that everyone is a single-issue voter deep down:
No endorsement of any single issue qualifies a person to hold public office. Being pro-life does not make a person a good governor, mayor, or president. But there are numerous single issues that disqualify a person from public office. For example, any candidate who endorsed bribery as a form of government efficiency would be disqualified, no matter what his party or platform was. Or a person who endorsed corporate fraud (say under $50 million) would be disqualified no matter what else he endorsed. Or a person who said that no black people could hold office—on that single issue alone he would be unfit for office. Or a person who said that rape is only a misdemeanor—that single issue would end his political career. These examples could go on and on. Everybody knows a single issue that for them would disqualify a candidate for office.
It’s the same with marriage. No one quality makes a good wife or husband, but some qualities would make a person unacceptable. For example, back when I was thinking about getting married, not liking cats would not have disqualified a woman as my wife, but not liking people would. Drinking coffee would not, but drinking whiskey would. Kissing dogs wouldn’t, but kissing the mailman would. And so on. Being a single-issue fiancé does not mean that only one issue matters. It means that some issues may matter enough to break off the relationship.
So it is with politics. You have to decide what those issues are for you. What do you think disqualifies a person from holding public office? I believe that the endorsement of the right to kill unborn children disqualifies a person from any position of public office. It’s simply the same as saying that the endorsement of racism, fraud, or bribery would disqualify him—except that child-killing is more serious than those.
See the whole article here.
HT: Denny Burk
A Pilgrim's Friend 
“It’s simply the same as saying that the endorsement of racism, fraud, or bribery would disqualify him—except that child-killing is more serious than those.”
I’m not sure I buy the argument that these things that you state are the equivalent of abortion. On a fundamental level, there is a deep divide in the hearts and minds of Americans on the issue of abortion. Those other issues … not so much.
So the question becomes – does the fact that reasonable people disagree on abortion make it different from the other issues that reasonable people don’t disagree about?
I have to say, “Yes.”
Note that I’m not saying that you’re not justified in withholding your vote from non-prolife candidates; I’m simply saying that the reasoning used here is flawed.
I think your single issue (as expressed) isn’t thought out very carefully. I mean, really…ANY public office? County Auditor? Port Commissioner? Secretary of Transportation? They ALL have to be “pro-life”? Absurd. I can understand taking that stand for those elected specifically to make laws, but there are tons of elected officials who have no interface whatsoever with the issue of abortion in their official capacity. Their personal opinions on issues having nothing to do with their job aren’t reasons to either qualify OR disqualify them.