Former South Bend, Ind., mayor Pete Buttigieg has soared in New Hampshire polls over the past month. On Jan. 15, he stood at 13.3 percent in the RealClearPolitics average. On the eve of the primary, he was at more than 21 percent. Former vice president Joe Biden has gone in the opposite direction over the same period, drifting from slightly more than 23 percent to 11 percent. In the poll averages, Biden now ranks (barely) below both Sens. Amy Klobuchar (D-Minn.) and Elizabeth Warren (D-Mass.).

Buttigieg has been soaring after the Iowa caucuses (which were called in his favor in terms of definitive delegates only in the past day or so). Klobuchar skewered him in Friday’s debate on experience — an attack Biden ran with over the weekend — but it is far from clear that any of that damaged Buttigieg’s momentum. He is playing the role of outsider; he hopes the attacks will confirm his argument that the “insiders” are now worried. Buttigieg, like all the Democrats, has the challenge of slowing down Sen. Bernie Sanders (I-Vt.), who leads in virtually every public poll going into the vote Tuesday. What, then, can Buttigieg hope to accomplish, and what must he worry about?

First, Buttigieg got a big lift in Iowa by beating the expectations game. There, as in New Hampshire, the betting was that Sanders would win, maybe handily. While chances are slim that Buttigieg could actually win Tuesday, finishing within a few points of Sanders and keeping Sanders under 30 percent would be positive news in a state that Sanders won with 60 percent of the vote in 2016. A close finish would also demonstrate that he can take hits from multiple opponents on experience. And certainly the greater Biden’s wipeout, the better Buttigieg’s claim to becoming the moderate alternative to Biden.

Second, Buttigieg will have to struggle not only with Sanders for headlines, but also with Klobuchar, who may well come in third and earn plaudits as the new Cinderella candidate and the feasible moderate to go up against Sanders. The closer she is to Buttigieg, the more muddled the moderate “lane” becomes. Klobuchar has risen not only because of her shots at Buttigieg but also by posing as the younger (but not too young) and sharper alternative to Biden.

Third, in his remarks Tuesday night, Buttigieg has a chance to ring the electability alarm, playing into panic in some Democratic quarters that Sanders could jump out to a significant lead and never look back. Buttigieg’s message to date has been that he can unite the party and the country, while Sanders seeks to divide. He might need to be more direct: A socialist will scare off middle America and hand the election to President Trump. The most recent Gallup poll adds weight to that argument. Gallup asked whether voters would be likely to vote against candidates from various groups (e.g. female, African American). Gallup found: “Just one group tested — socialists — receives majority opposition. Less than half of Americans, 45%, say they would vote for a socialist for president, while 53% say they would not.”

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Fourth, Buttigieg still has not solved his problem with African American voters. Having demonstrated his viability with white voters, Buttigieg hopes to leave New Hampshire with a plausible case to be made to nonwhite voters in Nevada and South Carolina, where former New York mayor Mike Bloomberg, who has made significant progress among African American voters, will not be on the ballot. For African American voters who simply cannot fathom what a second Trump term will look like, Buttigieg wants to be able to present himself as really the only means of tripping up Sanders before Super Tuesday. With Nevada and South Carolina voters looking on, Buttigieg may speak to those voters who will make up a more substantial share of the vote from here on out.

In sum, Buttigieg is fighting on multiple fronts, seeking to slow down Sanders, crush Biden and minimize the success of Klobuchar. If he finishes a close second and puts distance between himself and those two moderates, it will be a very good night for him.

The better Biden embraces personal vulnerability over electoral invincibility, says Post columnist Karen Tumulty. (The Washington Post)

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