Sen. Bernie Sanders (I., Vt.) is having a rough week. A new poll by Morning Consult has him trailing former Vice President Joe Biden, fresh off his official entry into the Democratic primary, by 14 percentage points. Another poll of New Hampshire voters shows Sanders tied for second with South Bend Mayor Pete Buttigieg at 12 percent, with Biden leading the pack at 20 percent.

Both polls were conducted in the wake of Sanders' controversial proposal to extend voting rights to incarcerated felons, including murderers and terrorists such as Boston Marathon bomber Dzhokhar Tsarnaev. The candidate has since doubled down on his position, saying he envisions a "vibrant democracy" in which even "terrible people" like Tsarnaev are allowed to participate in elections.

Rival Democratic candidates did not exactly share Bernie's views on the issue. Buttigieg, for example, succinctly rejected the idea that incarcerated felons be given the right to vote. Sen. Kamala Harris (D., Calif.), on the other hand, initially expressed a willingness to consider the idea, but promptly backtracked, stating that violent prisoners "should be deprived of their rights" to vote.

Harris' actions make sense when you consider the massive popular opposition to extending voting rights to all prisoners. According to a recent poll, just 15 percent of Americans agree with Sanders' position that every prisoner, regardless of their crimes, should be allowed to participate in elections; 75 percent said they disagreed. The remaining 20 percent said they would support giving voting rights to prisoners convicted of non-violent offenses.

Few issues in American politics are this lopsided, but Sanders is unlikely to back down anytime soon. In fact, he authored a USA Today op-ed on Tuesday offering "no apologies" for stating his views on prisoner voting rights.

"If we are serious about calling ourselves a democracy, we must firmly establish that the right to vote is an inalienable and universal principle that applies to all American citizens 18 years and older. Period," Sanders wrote. "[P]unishment for a crime, or keeping dangerous people behind bars, does not cause people to lose their rights to citizenship. It should not cause them to lose their right to vote."