Associated Press

Rep. David Rivera's (R-Fla.) career has become almost comical. The conservative freshman has been investigated by the FBI, IRS, Miami-Dade Police Department's public corruption unit, the Miami-Dade State Attorney's Office, and Florida Department of Law Enforcement over allegations that he abused his office in the state legislature and repeatedly lied on financial disclosure forms.

And now, things have managed to get worse.

The FBI and Miami-Dade police have opened separate criminal investigations into the campaign of a Democratic congressional candidate who, vendors say, was aided by GOP Rep. David Rivera.

Federal agents gathered campaign records, invoices and began interviewing employees at two mail and data companies used by Democrat Justin Lamar Sternad's primary campaign. Sternad spent about $43,000 in unreported cash and checks on mail services, a witness told The Herald and authorities. Some of the money was stuffed in envelopes bulging with $100 bills.

Federal law required Sternad to quickly report any contributions -- including loans -- just before the Aug. 14 primary, which he lost to Democrat Joe Garcia, a longtime Rivera rival who Sternad bashed in one of his 11 mailers.

Rivera, investigators suspect, was behind the sophisticated mail campaign run by Sternad, who was an unknown political newcomer and hotel night auditor.

It appears to have been a rather clumsy scheme. Congressman Rivera, fearful that Joe Garcia may defeat him in November, allegedly arranged for Sternad to run in the Democratic primary.

As part of Sternad's "campaign" (I use the word loosely), he quietly spent tens of thousands of dollars, in cash, on anti-Garcia mailings -- through the same local printer Rivera has used. Where'd all this unreported cash come from? Law enforcement officials would like to find out.

What's more, Sternad's family income is about $30,000. How he was able to spend $43,000 in unreported cash on direct mail is also unclear. The money didn't come from legal donors -- his total cash on hand as of late July was $120.97.

Rivera claims he doesn't even know Sternad, but there's ample evidence to the contrary, including the fact that one of Rivera's Republican allies ran Sterna'd campaign.

The Republican congressman told the Miami Herald that the paper is in league with Democrats as part of some kind of conspiracy against him.

House Majority Leader Eric Cantor (R-Va.) had vowed a "zero tolerance" policy when it comes to misdeeds from congressional Republicans, but has shown no interest in addressing Rivera's multiple and ongoing scandals.