A botched Oklahoma execution Tuesday in Oklahoma threatens to undermine lethal injection as Americans' most palatable form of capital punishment.

A 2007 Associated Press-Ipsos poll found 69 percent of Americans picking lethal injection as their preferred method for carrying out death sentences. All other methods were in single digits, including hanging (9 percent), electrocution (6 percent), firing squad (8 percent) and the gas chamber (5 percent). While there is precious little new data, the results appear to be stable over time. A 1991 Gallup poll found 66 percent preferring lethal injections (10 percent electric chair, 6 percent gas chamber, 3 percent firing squad, 3 percent hanging).

Why do Americans have such a strong preference for lethal injection? While executing murderers is an long American tradition, the practice seems to be something people tolerate but don't revel in. Just 15 percent said they would want to watch Timothy McVeigh's execution on television in 2001, according to a CBS News poll at the time. Today, the public prefers capital punishment that is fair, out of sight, and performed as humanely as possible. Lethal injection is seen as the best of a series of bad options.

How we put people to death seems in line with public opinion on the issue. Lethal injection is today's dominant form of execution; 69 percent of executions in 2011 used the method, according to the Bureau of Justice Statistics -- and it's the default method in almost all states employing capital punishment.  But the method has recently run into a number of practical hurdles, including unwilling doctors and unavailable drugs.

The impact of Oklahoma's botched execution of inmate Clayton Lockett on popular support for lethal injection or the death penalty overall is unclear. Many botched injections have occurred both before and after the 2007 AP poll, and while support for the death penalty has declined noticeably in recent years, it is still favored by a majority of Americans. But with two problematic executions in the first four months of 2014, states may take a fresh look at whether to continue the practice amid logistical challenges. If discontinued, Americans don't have much appetite for anything else.

Peyton M. Craighill contributed to this report.

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With capital punishment dominating headlines, PostTV looks at the latest statistics on the death penalty in the United States, and in the 21 other countries that executed inmates in 2013. (Davin Coburn/The Washington Post)