[We want to hear from you. What do you want to see from the Democratic debates?]

Like most of her rivals in the Democratic primary race, Ms. Klobuchar has been unable to break out of the pack. She is polling in the low single digits and has failed to command the kind of news media attention that some of her competitors have received.

One of those competitors, Senator Elizabeth Warren of Massachusetts, has established herself as the policy-minded candidate in the race with a steady stream of detailed proposals. Ms. Klobuchar is pursuing a more moderate agenda than Ms. Warren is, and her proposals for the first 100 days are described only briefly.

But with her announcement on Tuesday, Ms. Klobuchar will be able to credibly argue that she has presented an extensive blueprint for what the early days of her administration would look like — a period of time that is a blank canvas for many candidates.

Some of Ms. Klobuchar’s plans deal with high-profile issues, both foreign and domestic. She would rejoin the Paris climate accord and seek to re-enter the Iran nuclear agreement. She would also protect from deportation the young undocumented immigrants known as Dreamers.

Other plans address narrower subjects, like cracking down on illegal robocalls and investigating deceptive practices by travel-booking websites.