Republican National Committee's new ad: "Stop Hillary"

Former U.S. Secretary of State Hillary Clinton speaks at an award ceremony for the 2015 Toner Prize for Excellence in Political Reporting March 23, 2015 in Washington, DC.

Win McNamee, Getty Images

As Hillary Clinton reportedly prepares to announce her 2016 presidential bid this weekend, the Republican National Committee is out with a new ad that attempts to sow doubt about Clinton's candidacy.

The ad, titled "Stop Hillary," uses various sound bytes from news reports to target Clinton on a number of fronts, including her use of a private email server to conduct business as secretary of state, her effort to "reset" U.S.-Russia relations in President Obama's first term, and her family foundation's receipt of money from foreign governments.

"Used her personal email account to conduct official business," one byte intones.

"Wanted to reset relations with Russia," adds another.

"Taking millions of dollars from foreign governments," says a third.

"This is just par for the course for the Clintons, they're always a little bit secretive," says the last byte. The onscreen text in the final frame reads, "STAND WITH US #STOPHILLARY"

The RNC says the ad, a paid online spot targeting swing voters in six battleground states, is part of its broader "Stop Hillary" campaign.

"From the East Wing to the State Department, Hillary Clinton has left a trail of secrecy, scandal and failed liberal policies that no image consultant can erase," said RNC Chairman Reince Priebus in a press release. "Voters want to elect someone they can trust and Hillary's record proves that she cannot be trusted. We must 'Stop Hillary.'"

While no Democrat has formally announced a 2016 candidacy, Clinton has already emerged as an overwhelming favorite for the party's nomination.

Republicans, as the RNC ad attests, have already started behaving as if they're facing Clinton in a general election. The GOP's crowded roster of candidates and potential candidates regularly attack Clinton in their public appearances, and those attacks are likely to intensify as the campaign takes off in earnest.