A uniformed officer in a police cruiser sat outside Sen. Marco Rubio's (R-Fla.) Miami home Tuesday night, NBC Miami reports, although the lawmaker was away in Washington D.C.
A threat "deemed credible enough to merit police protection" has been made against the rising Republican star and potential presidential running mate, according to the Miami Herald, prompting West Miami Police officials to coordinate protection with U.S. Capitol Police.
Rubio's office said no additional information would be released for now, according to the Herald report.
The freshman senator is scheduled to deliver a "major address" on foreign policy Wednesday at D.C.'s Brookings Institution.
Rubio thought to be "auditioning" as Mitt Romney's running mate as he joins the candidate on campaign stops in Pennsylvania.
Romney refuses to confirm whether he's officially considering Rubio. And he adamantly opposes Rubio's proposed Republican compromise to the DREAM act, which permits citizenship for some undocumented immigrants who attend college or serve in the military.
Rubio, a Cuban-American, has been criticized by some in the local Latino population for being on the wrong side of issues crucial to Hispanics. He has been greeted with cries of "No Somos Rubios" -- translated as "We aren't Rubios," a phrase in which the senator's last name is also interpreted as "blond" or "fair" as in non-Hispanic.
On Valentine's Day, South Florida protestors appeared at his Miami office to voice their concerns that the senator was showing too much love for the wealthy and not enough for the state's working families. See photos from the protest here.
Rubio, who recently got into hot water for embellishing details of his parents' Cuban immigration, releases his memoir "An American Son" this June.
Click below for a slideshow of Rubio, from his South Florida campaign to his recent appearances with Romney: