Elrich, who is also an at-large council member, was certified as the winner of the six-way race for the Democratic nomination on Monday, squeaking past businessman David Blair by 79 votes.
Blair has until Thursday to request a recount.
Elrich’s victory spurred Floreen — a 16-year council member — to switch her registration to unaffiliated and begin gathering the 7,244 signatures needed for her to appear on the November ballot.
Floreen and Elrich represent two facets of the Democratic Party; Elrich, on the left, has supported social causes while also cautioning about the ill effects of overdevelopment, while Floreen, a moderate, enjoys support among business leaders.
Leggett, a former chair of the state Democratic Party, joins several other Democratic leaders in the largely blue county who say they respect Floreen but will support Elrich in the race.
Leggett did not endorse any of the six Democrats in the June 26 primary. He said he has been friends with both Elrich and Floreen for years and that either one would make a good county executive.
Floreen has called the prospect of an Elrich administration a “disaster.”
“I hate to see this sort of conflict, but she feels very strongly about what she’s doing,” Leggett said, calling Floreen a “very strong candidate.”
“She has to get the signatures, so this is not done yet.”