The angry, old man socialist routine isn't working out so well for Sen. Bernie Sanders, I-Vt. As I've been anticipating for several weeks, Sen. Elizabeth Warren, D-Mass., is catching up to him, at least in two polls.

In the Economist/YouGov poll, since last week former vice president Joe Biden is down one point but leads nationally with 26 percent; Warren, however, gained five points in a week and Sanders lost four, leaving them at 16 percent and 12 percent, respectively. South Bend, Indiana, Mayor Pete Buttigieg comes in with 8 percent, and Sen. Kamala Harris, D-Calif., with 6 percent. Everyone else is at 3 percent or less.

That 12 percent is one of worst results Sanders has gotten in any national poll; whether it is an outlier or not remains to be seen. (To make matters worse, Sanders has the highest unfavorable rating of any Democratic candidate: 47 percent have a somewhat or very unfavorable opinion of him.)

Moving over to Nevada, for which there has been a scarcity of public polling, the Monmouth poll finds that "Biden holds a clear lead with 36 percent support among registered Democrats and unaffiliated voters who are likely to attend the February 2020 Nevada caucuses. He is followed by Warren at 19 percent, Sanders at 13 percent, South Bend Mayor Pete Buttigieg at 7 percent, and California Sen. Kamala Harris at 6 percent."

We can surmise that Warren is doing well because she has carved out an identity as the most policy-driven ("I have a plan for that!") progressive in the race, someone who stays until the last autograph is signed and the last selfie is taken. She exudes tenacity and seriousness; she's steadfastly avoided calling out her Democratic opponents, at least by name.

Figuring out why Sanders is sinking is a bit harder. There are several possibilities, and none is mutually exclusive.

One explanation is that voters simply like Warren more.

Another theory would be that Sanders's support was always "soft," and he's simply stopped benefiting from name ID as other candidates become more well known. If that's the case, he's in for more rough seas since a sizable chunk of primary voters still don't know much about Buttigieg and Harris, the other top contenders.

Finally, it's possible that doubling down on socialism and maintaining his angry, get-off-my-lawn countenance isn't endearing himself to a Democratic electorate that desperately wants to win and is frankly tired of grumpy old, male politicians. If this is the case, doubling down on socialism and trying to define the term as he did in a speech on Wednesday probably wasn't a good idea — and wasn't even new. (CBS News notes, "Many of Sanders' proposals, including Medicare for all, free public college and a $15 minimum wage, fall under the umbrella of democratic socialism. Those policies were the centerpieces of Sanders' 2016 campaign — he gave a similar speech in November 2015 defending democratic socialism.")

There is a reason Sanders's opponents are snickering over his choice to identify with a very unpopular ideology. (Edward-Isaac Dovere writes, "His opponents' critiques line up: Sanders is promising pipe dreams that most people don't even really want, and certainly won't get, and along the way he's playing right into Trump's 'Democrats are socialists' scare tactics, in addition to his subtler attack on Democrats-that they always promise big but rarely deliver.") It's the equivalent of hanging a "kick me" sign around your neck.

One last but important point: Over and over again we see that the only candidates getting real traction are Biden, Sanders, Warren, Harris and Buttigieg. The others might not make it through the fall debates where the threshold for support goes to 2 percent. Then the race may start in earnest.

Jennifer Rubin writes reported opinion for The Washington Post.