Former Sen. Bob Kerrey (D-Neb.) has decided to run for Senate in Nebraska, according to a report by the Washington Post.

Only three weeks ago, Kerrey announced he would not run for Senate. The change of heart is seen as a major boost for Democrats, who were unlikely to compete to hold the seat of retiring Sen. Ben Nelson absent a top-tier candidate.

Kerrey, a former governor and two-term Senator, has statewide star power similar to Nelson’s, and his entrance is expected to change the dynamics of the race. The current GOP field includes state Attorney General Jon Bruning, state Treasurer Don Stenberg and state Sen. Deb Fischer.

After he left the Senate in 2001, Kerrey moved to New York City to serve as president of the New School University in Greenwich Village. Before his earlier decision against running, Democrats had stressed his continued business interests in Nebraska, while Republicans emphasized his New York City residence.

Roll Call changed its rating of the Nebraska race to Likely Republican after Nelson’s retirement announcement but will be re-evaluating that rating in light of Kerrey’s move.