The GOP caucus elected Sen. E.J. Pipkin as the new minority whip. The leadership elections followed the resignation of Minority Leader Allan H. Kittleman over his plans to introduce legislation to legalize same-sex civil unions in Maryland.
Jacobs, who represents Harford and Cecil counties, said the Senate Republicans' main goal this year will be to "protect constituents who are hurting financially in these tough economic times."
She said she would continue to fight against new taxes and to make the state more hospitable to private businesses. The Senate's only female Republican, Jacobs appears to be the first woman to lead the Senate minority caucus.
The turn of events capped an eventful week for the 12-member group, which suddenly shifted its leadership from two of the more moderate Republicans to two of the more conservative ones.
On Tuesday, Kittleman resigned because he said he believed his push for civil unions was causing friction within the caucus. Fellow Republicans stressed that they had not asked Kittleman to step down and were shocked at his decision.
Kittleman's minority whip, Sen. David Brinkley of Frederick County and a supporter of legalizing medical marijuana, had been in the running for the leadership position.
But in a secret-ballot election Friday afternoon, colleagues chose Jacobs over Brinkley by a narrow margin, according to several Republicans present. Pipkin, of the Eastern Shore, was selected over Sen. Edward R. Reilly of Anne Arundel County.
Pipkin said his interests in tax-fighting and job creation will serve him well in his new position.
"What I am excited about is that this seems to be the year where a fair amount of time will be spent discussing the size and scope of government spending," Pipkin said.
Jacobs has been in the Senate for a dozen years. Pipkin was elected in 2002.
In the previous two legislative sessions, Jacobs served as minority whip, but in December, the caucus replaced her with Brinkley. Jacobs said Friday that her husband had a cancer scare about the time she was voted out of office, which she said prompted her to be less than enthusiastic about the whip position.
But in recent weeks, doctors assured Bruce Jacobs that his health is fine, Nancy Jacobs said.
Asked about her historic election as the first female Senate minority leader, Jacobs said she was "just happy the 11 men in my caucus think I'm worthy. That's special."
A previous version of this story omitted the name of a previous woman floor leader in the Maryland Senate. Democratic Sen. Rosalie Abrams served as majority leader from 1978-1982.