Senate Majority Leader Harry Reid isn’t on the ballot in 2012. But the fate of his leadership position in Washington and his influence in Nevada politics are.

In recent months, Reid has begun trying to muscle favored Nevada Democratic primary candidate, Rep. Shelley Berkley, past multimillionaire Las Vegas businessman Byron Georgiou (D), while also attempting to chill D.C. political action committees and lobbyists from donating to the likely Republican nominee, appointed Sen. Dean Heller.

Washington, D.C., PACs usually support incumbent Senators and decline to contribute to challengers, regardless of political party. But according to a Republican lobbyist whose firm has relationships on both sides of the aisle, Reid is urging Washington’s money people to treat the Nevada race as an open contest given that Heller was appointed, telling the downtown community that this campaign could determine whether he remains Majority Leader.

“Many PACs are not including Heller in their giving,” this lobbyist said.

Reid and Georgiou haven’t always been enemies. Georgiou has been a major donor to the Democratic Senatorial Campaign Committee, which also has endorsed Berkley, and was previously appointed by Reid to serve on the federal Financial Crisis Inquiry Commission. But their relationship has since soured, with Reid moving deliberately in Nevada to make sure Democrats know Berkley is his candidate.

And on Tuesday, Reid accused Georgiou at a Capitol Hill news conference of being less than truthful with the Majority Leader about his business background when he appointed the Democratic activist to the FCIC. Additionally, news reports have suggested Georgiou might have acted unethically during his tenure at the FCIC. Regarding his appointment of Georgiou to the commission, Reid said pointedly, “I wish I hadn’t done that.”

One Democratic Senate source confirmed that Reid views Georgiou as a fatally flawed candidate and that the Majority Leader is intent on doing whatever is necessary to ensure Berkley’s victory in the primary. Other sources following the race have suggested that Reid was influenced to back Berkley by Democratic pollster Mark Mellman, a Berkley adviser who helped guide Reid through a tough 2010 re-election bid and is highly respected by the Majority Leader.

“He thinks she is the strongest candidate to create jobs, protect Medicare and represent the people of Nevada in the Senate,” a senior aide to Reid said.

The DSCC has also endorsed Berkley, and committee Chairwoman Patty Murray (Wash.) said Reid’s backing of the Congresswoman is significant. “Sen. Reid is well-known, he just won a great race and obviously his voice carries,” she said during a brief interview.

Georgiou, responding in a prepared statement, charged Reid and other “Washington insiders” with making false accusations about his background and service on the FCIC in an effort to scare him out of the race. The businessman said it would not work and vowed to continue his campaign.

“Far from being intimidated, the false attacks aimed at my candidacy have only served to fortify my resolve to stand against the unholy alliance between Washington and Wall Street that wrecked our economy and far too many lives, and strengthened my commitment to run for the U.S. Senate and win,” Georgiou said.

It is not uncommon for Congressional leaders to intervene in party primaries back home. In 2010, Senate Minority Leader Mitch McConnell (R) endorsed then-Kentucky Secretary of State Trey Grayson and worked hard to aid his campaign, only to see now-Sen. Rand Paul win the GOP primary. Reid himself played behind the scenes in the 2010 Republican Senate primary in Nevada in an effort to ensure the defeat of Sue Lowden, the candidate widely thought to have been Reid’s strongest general election opponent.

Sharron Angle (R) ultimately won the Republican primary but lost to Reid by 5 points, a stunning margin considering how unpopular the Democrat was with Nevada voters. Beyond Angle’s flawed candidacy, Reid’s victory was attributed mainly to a get-out-the-vote operation described by many political analysts as the best non-presidential ground game ever executed.

Reid is planning to make this machine available to Berkley, both in the primary and the general election, which is a key reason Nevada Democrats give Georgiou no chance of winning the primary. The senior Reid aide said the Majority Leader has spoken up in recent days because Georgiou had been telling Nevada Democrats that Reid supports him — and the Senator wanted to set the record straight.

“That was clearly a message that he’s not happy with him running,” said Assemblyman Tick Segerblom (D), who represents Las Vegas. “He’s made his decision on Shelley and now is maybe not-so-gently trying to push Byron to the side.”

One Democratic consultant with no ties to either candidate said it is odd Georgiou is going to pass up great opportunities to win a House seat. Georgiou finished second in the Democratic primary in House races in San Diego in 1990 and 1992.

“He simply can’t” overcome Reid and Berkley, the source said. “If the Republicans can’t beat the Democrats in the Nevada Senate race in 2010, then I don’t see how an outsider Democrat beats the Democrats in 2012.”

Some Nevada Republicans argue that Georgiou offers Democrats a better chance against Heller, given his profile as an outsider and a businessman. They contend Georgiou might perform better in this swing state in an election that features the presidential contest at the top of the ticket. But Berkley’s supporters disagree.

A source close to the Congresswoman emphasized that she “has her own top-notch team and runs her own campaign,” though the source conceded that Reid’s assistance gives her the leg up.

“Reid has held two fundraisers on her behalf and has made the Nevada State Democratic Party what it is today. And that infrastructure puts her at a serious advantage,” the source said. Of the two fundraisers Reid has hosted for Berkley, one was in Nevada and the other in Washington, D.C.

Billy Vassiliadis, a Democratic consultant in Nevada and an adviser to Reid’s campaign last year, said Reid’s goal is to simply ensure a Democrat wins the general election next year.

“He’s got his majority leadership at stake here,” Vassiliadis said. “Given the retirements from senior Democratic Senators, this is about the majority. … Common sense would probably say that the Senator would be really troubled, but I think he’s just begun to swing.”

Correction: June 22, 2011

An earlier version of this article misspelled Democratic pollster Mark Mellman’s name.