To say that Senator Bernie Sanders’ proposal to allow all felons to vote from behind bars has landed with a thud is a bit of an understatement. As compassionate and forgiving as he may feel Americans are, very few are ready to let the Boston Marathon bomber start casting votes, no matter how good he may look on the cover of Rolling Stone. But how bad of an idea is it and is it affecting his chances in the primary? Nathaniel Rakich at FiveThirtyEight crunched the numbers recently and they aren’t good.

As of now, at least, full re-enfranchisement doesn’t seem like a winning issue for Democrats. For example, President Trump’s re-election campaign attacked Sanders for his stance in the days after the town hall, calling it “deeply offensive” and pointing out it would allow domestic terrorists like the surviving Boston Marathon bomber to vote. Even among Democrats, the idea is controversial. The HuffPost/YouGov poll found that Democrats opposed Sanders’s position 46 percent to 38 percent; Quinnipiac found that Democratic voters were about evenly divided on the issue. Bills to eliminate felony disenfranchisement failed to pass the legislature this year in both New Mexico and Hawaii, where Democrats have full control of state government. And no other Democratic presidential candidate has yet joined Sanders in calling for all prisoners to be allowed to vote.

The new Morning Consult poll came out today and Biden is now leading Sanders by 20 points nationally. That’s the same margin they’re seeing in the combined early primary state polls. It’s impossible to say precisely how much of Bernie’s decline can be blamed on that felon voting proposal, but it’s obviously not helping.

The reasons to suspend the voting privileges of felons serving time are many. And as the linked article shows, even Democrats aren’t generally wild about the idea of changing that. The idea of allowing them to vote after leaving prison but still on probation or under house arrest isn’t much more popular. But once they’ve fully served their time, there’s actually a fairly healthy percentage of the country that believes they should be able to return to the voting booth.

Personally, that’s pretty much how I feel about it. The theory is that if you’ve broken the law, been convicted and sentenced, once you’ve “paid your debt to society” you’re supposed to be allowed to return to the flock. The reality is very different for ex-convicts of course. Their record follows them when they apply for jobs or attempt to form new personal relationships. It’s even worse for sex offenders, who often have to spend the rest of their lives on registry lists and are limited as to where they can live.

But voting just strikes me as different. In the examples I cited above, it is the convict’s fellow citizens who continue to “punish” them after release. But that doesn’t mean the government should be able to do so. While it may be an unpopular opinion in some circles, I’m fine with allowing those who complete all of their punishment back to the voting booth. But Bernie’s idea is simply several bridges too far.