Former Maryland governor Martin O'Malley announces his intention to seek the Democratic presidential nomination during a speech on May 30. (Jim Bourg/Reuters)

Democratic presidential hopeful Martin O'Malley sent a tartly worded e-mail to supporters Friday saying he is "pissed" by congressional inaction on gun control and asking them to stand with him in an effort to toughen laws after this week's massacre at a Charleston, S.C., church.

"It's time we called this what it is: a national crisis," O'Malley said in the e-mail, which carried the subject header "I'm pissed" and included links to a Web page to provide contact information to his campaign. He used the word "pissed" four more times in the e-mail.

O'Malley's choice of words -- more common among teenagers than presidential candidates -- seemed a gambit to attract attention to a campaign mired in the low single digits in early-state polls. But a spokeswoman said the tone was a true reflection of how the former Maryland governor, who has used salty language on other recent occasions, feels about the issue.

[It’s not just Hillary. Sen. Bernie Sanders is outdrawing Martin O’Malley.]

In the e-mail, O'Malley pointed to his record as governor, which included passage in 2013 of a wide-ranging gun-safety bill. On the national level, he is calling for an assault weapons ban, stricter background checks and efforts to prevent "straw purchases" of guns, such as fingerprinting requirements, which Maryland implemented.

O'Malley's proposals are more specific than anything his Democratic rivals, including former secretary of state Hillary Rodham Clinton and Sen. Bernie Sanders (I-Vt.), have suggested in recent days. In the past, Clinton has supported banning assault weapons and other measures favored by gun-control advocates. Sanders has a mixed record that includes voting against the landmark Brady bill that required background checks and a waiting period before buying a firearm.

"I'm pissed that after working hard in the state of Maryland to pass real gun control — laws that banned high-magazine weapons, increased licensing standards, and required fingerprinting for handgun purchasers — Congress continues to drop the ball," O'Malley wrote.

He also knocked Republicans running for president, saying none of them have been "even close to being right on this issue."

O'Malley's e-mail followed an appearance earlier Friday on MSNBC's "Morning Joe," in which he said -- in less colorful terms -- that the shootings this week should be a call to action on gun control and mental health issues.

[O’Malley: GOP economic argument is 'patently bulls—']

In late April, O'Malley raised eyebrows when during an interview on National Public Radio, he referred to a Republican economic argument as "patently bulls---." Afterward, he sent an email to supporters with the subject header, "Yeah, I said it." O'Malley used the same epithet in a conversation with reporters during a recent trip to the early nominating state of New Hampshire.