Comptroller Peter Franchot announced his backing of Clinton Monday morning in an email to supporters. Franchot praised her experience, as well as her campaign promises to lower the cost of college and invest in biotechnology.
In endorsing Clinton, Franchot becomes the latest Maryland politician to support the establishment favorite over O'Malley's long-shot bid for the Democratic nomination.
Long before Clinton officially launched her campaign, she secured support from Sens. Barbara A. Mikulski and Ben Cardin in Dec. 2014. She won endorsements from most of the state's Democratic congressional delegation, including Minority Whip Steny Hoyer, Rep. John Delaney, Rep. Chris Van Hollen.
In her second bid for the presidency, Clinton has secured what analysts called an unprecedented number of endorsements in advance of the primary contests.
O'Malley, meanwhile, has lagged far behind in both fundraising and endorsements, while his support has hovered near 1 percent in polls. His first debate performance, widely considered a strong showing, failed to give him a bump.
On Monday, his campaign promoted his performance over the weekend at the Iowa Democratic Party's Jefferson-Jackson Dinner as a potential "breakout moment."
Back in Maryland, it hasn't earned him any new endorsements yet.
O'Malley frequently sparred with Franchot during the eight years they sat together on the three-member Board of Public Works, which oversees state contacts. In endorsing Clinton on Monday, Franchot praised as her a progressive who can get things done - the exact same pitch O'Malley has been making on his own behalf.
Franchot wrote that "it is my belief that Hillary Clinton’s incomparable record of experience – as one of the nation’s most respected public education advocates, as First Lady, as a United States Senator and as Secretary of State – will guide her efforts to balance her promises of social responsibility with a commitment to fiscal responsibility. "
Franchot is one of a handful of politicians elected statewide in Maryland and is widely considered a potential Democratic candidate for governor in 2018. Since Republican Gov. Larry Hogan took office in January, Franchot has often sided with Hogan on spending matters and criticizing O'Malley's tenure.
Attorney General Brian Frosh, another Democrat elected statewide, is backing O'Malley's campaign bid and campaigned for him in New Hampshire in August. Prince George's County Executive Rushern Baker also supports O'Malley.
O'Malley's campaign said he has received "more than 50 Maryland endorsements," including Frosh, several former state leaders and current members of the General Assembly. In the past, spokeswoman Haley Morris has downplayed the significance of Maryland politicians lining up behind Clinton. In May, she said, "the establishment backing the establishment is the oldest story in politics."