Sen. Michael F. Bennet (D-Colo.) at the Capitol on Jan. 24. (J. Scott Applewhite/AP)
Opinion writer

In case you missed it, the Democratic presidential primary field got word about two new entrants this week: Steve Bullock (D-Mont.), a popular governor in a red state with a passion for campaign finance reform, and Sen. Michael F. Bennet (D-Colo.), also a moderate and a centrist in a body that has few of them. Bennet is well-regarded by peers, knowledgeable on health care and credited with recently chewing out Sen. Ted Cruz (R-Tex.) on the Senate floor.

And neither is a household name outside his state. Both are white men; neither is likely to appeal to the left wing of the party, nor does either have a national organization. For one of them to get the nomination, former vice president Joe Biden and the batch of better-known moderates (e.g., Minnesota Sen. Amy Klobuchar) as well as fresh newcomers such as South Bend, Ind., Mayor Pete Buttigieg would have to fail. Charitably speaking, they have a very tiny chance of success.

Why then are they in the race, and why should Democrats care that they are in it? One could surmise that they are auditioning for the VP slot to provide balance geographically or ideologically if, say, Sen. Kamala D. Harris (D-Calif.) or Sen. Elizabeth Warren (D-Mass.) is the nominee. One could also imagine one of them becoming a capable Cabinet secretary if a Democratic president wins. But neither the vice president nor Cabinet secretaries need to have been presidential candidates. As for personal benefit, if one never breaks 1 or 2 percent in the polls, as is very possible, don’t imagine they are going to get rich off book sales or speaking gigs.

There are, I think, three reasons to get in the race.

First, well, you never know. Maybe one of them will catch fire, akin to Buttigieg’s rise, just before Iowa and sneak into a top three or five spot.

Second, they are both relatively young in political years, with long careers ahead. Anyone who has run for president will say it is really helpful if you’ve done it before. This can be their “before” — a way to learn, make connections and build a fundraising network to be used when they put together a more plausible run.

Those reasons are personal to the candidate, but there is a third reason very much in the interest of the party and the country: to remind the Democratic voters and the top-tier candidates that the majority of the country is not far-left, that the presidential nominee needs people like their constituents to win back the White House and that what they dream up in a policy paper may fly in the face of even Democratic opinion. Put differently, they are there to add ballast to the center-left and prevent avoidable train wrecks, the big one being the nomination of Sen. Bernie Sanders (I-Vt.). Sanders, of course, seems entirely capable of falling over his own feet, but their presence is also encouragement to the Mayor Petes and the Kamalas that they can be progressive without going off the deep end.

None of this is to say these two newcomers are unserious or insincere. Every presidential candidate at some point thinks he or she can be the One. They are, however, more important to the current and future health of a viable center-left than anything else. And that is no small thing.

Read more:

Joe Scarborough: Michael Bennet could be the answer to the question every Democrat is asking

Jennifer Rubin: Lessons in common-sense politics

David Ignatius: We may be headed toward a political realignment

Elaine C. Kamarck: Democrats are still center-left. They’ll stay there if they want to win.

David Ignatius: These ‘pragmatic progressives’ may be the future of the Democratic Party