Sen. Rand Paul, R-Ky., is courting establishment Republicans in his bid to take the Tea Party into the White House.

In the midst of a so-called "civil war" within the party, Paul is hoping his conciliatory moves won't alienate his own base, while potential rivals such as Sen. Ted Cruz, R-Texas, opt for confrontation. His campaign thinks this approach will keep him from being the establishment target in a GOP primary.

"I don't think he will be the top choice of everyone in a primary, but I also think he won't have quite the number of people trying to stop him that some others may have had who came through a similar path in the past,” Doug Stafford, executive director of RAND PAC, told the Washington Examiner. “If he runs, he will be the first choice of a significant portion of the voters and an acceptable one to many others. And that's important.”

That strategy has played out most notably in Paul's endorsement of his fellow Kentuckian, Minority Leader Mitch McConnell, over Tea Party challenger Matt Bevin.

“It’s really great,” McConnell said when asked of his relationship with Paul. Why? “He supported me for reelection, which I appreciate."

Sen. John McCain, R-Ariz., who called Paul a “wacko bird” last year in response to the younger senator's filibuster against President Obama's drone program policy, is now willing to give Paul the kind of praise rarely applied by the Senate "old bulls" to Cruz, who is disliked by many colleagues.

"I think he has conducted himself well,” McCain said when asked about how Paul’s relationship with Senate colleagues has changed since the drone program filibuster. “I have a very cordial relationship with him; I don't see any problems.”

That remark might reflect the different tactics deployed by Paul and Cruz in the biggest fight of 2013, the attempt to defund Obamacare, which angered Senate Republicans who feared being blamed for the government shutdown.

“Cruz was obviously way out front on that, and Rand wasn't,” FreedomWorks President Matt Kibbe noted. When the government shut down, Paul tried to "ratchet down" the rhetoric by hosting a coffee chat on the steps of the Capitol.

"My philosophy with other Republicans is peace and commerce with all," Paul told the Examiner.

In contrast to Paul, Cruz did not endorse his state's senior senator, John Cornyn, when Rep. Steve Stockman offered a weak primary challenge earlier this year.

"Ted Cruz can win about 18 percent and that's about it,” according to a source close to Paul, who handicapped Cruz’s prospects on condition of anonymity. “Rand is looking at things that unite people rather than divide people. Rand is looking at ways where he can build a 51-percent coalition or greater coalition in a Republican primary setting and he's looking at ways he can build a 51-percent coalition of Americans to actually elect him president."

That's not to say that Paul will concede the conservative wing of the party to Cruz in an eventual 2016 showdown, even if he doesn't expect to “run to the right” of his fellow Tea Partier.

“In a lot of ways, Rand is a more principled conservative because it's a lot more genuine, a lot more heartfelt from Rand,” the source suggested. “You know, Rand's felt this way, written this way, talked this way for 30 years, where[as], you know, Ted was clerking for William Rehnquist and was a very happy Bush Republican in the 2000s. With Ted, I think it is a lot of act there. Rand, it's all legitimate. In many ways, I think that Rand is a more genuine conservative than Ted.”

The question is, will Tea Party activists trying to unseat McConnell agree with that statement if he wins reelection with Paul’s help? Kibbe predicted the base won't hold a grudge.

"It's not Rand Paul's fault if Mitch McConnell survives; it just means that those of us that are trying to upgrade didn't get the job done," he said.

An aide to a congressional Republican associated with the Tea Party disagreed. “At some point in the future, the good guys are going to be on one side and Rand Paul is going to be on the other, and it's going to be very lonely on that other side,” the staffer argued, referring to primary election night. “He's going to be standing with Mitch McConnell on stage celebrating some kind of victory, and all the Tea Party folks are going to be angry.”

That election-night Image startled Tea Party Express chairwoman Amy Kremer, who initially said members would forgive Paul because they “understand that he is possibly running for a presidential campaign” — and because they expect to beat McConnell without his help.

“It's kind of the same as [New Jersey Gov. Chris] Christie getting blamed for Mitt Romney losing because of Christie hugging Obama and Hurricane Sandy," Kremer allowed when asked about what happens if Bevin loses. “I guess it could happen, yeah."

McConnell campaign manager Jesse Benton embodies the relationship between Rand Paul and party leadership. He worked on both of Ron Paul’s presidential campaigns and Rand Paul’s 2010 Senate race. He’s also married to Rand Paul’s niece.

While emphasizing that the two Kentucky senators have a “legitimate friendship” and that Paul believes McConnell is “a good conservative” senator, Benton argued that the alliance with McConnell provides Paul significant benefits in terms of broadening his appeal among mainstream Republicans.

“The friendship with McConnell is showing many folks that Rand is a serious person that wants to work for positive things, rather than just sort of tear things down and slash and burn, and is one of the most helpful things that Rand could have done for himself,” he told the Examiner. “As far as helping Rand politically, this is like an 80-20 [or] 90-10 kind of decision on the positive side."

That argument could hold true even in a contest as famously conservative as the Iowa Republican caucuses. In 2012, Rick Santorum won with 24.6-percent support. Mitt Romney received 24.5 percent of the vote, while Ron Paul placed third with 21.5 percent.

"I think you can do some calculus like this: Rand can hold on to a majority of people that came out for his dad, and bring even more young people into the party,” Benton said. “He is a traditionalist and a good Christian, and I think he'll be able to win more of the evangelical vote. He has a better relationship with the pro- Israel crowd than his dad did, and you can add a few points there. And then you can tap into some of the Romney people by showing that you're not trying to burn the establishment, whatever that is, to the ground, that he is reasonable and wants to unite people. And all the sudden, you've cobbled together a coalition putting you in the 30s, pushing 40 percent or more, and that's a recipe for winning early primaries and caucuses."

That’s probably the best-case scenario for Paul, but it requires that his alliance with the establishment — or détente, as the case may be — remains in place long enough for him to win some key victories.

“The establishment sees Rand Paul as a useful idiot,” a conservative source close to Paul and Cruz's camps, who would only talk about Cruz and Paul anonymously, said. “As soon as the primaries are over or, as soon as they feel that Ted Cruz has been pushed aside enough for the next race, they're going to turn on Rand and they're not going to be there for him and defend him when the attacks come from the left and the media turns their guns on him.”

Even if that's correct, the endorsement has already started to pay off for Paul, with McConnell supporting Kentucky legislation that would allow Paul to run for president and Senate at the same time.

Kibbe, whose organization has joined Paul in a class-action lawsuit against the National Security Agency's bulk collection of phone records, also suggested that rumors of a friendship between Paul and establishment Republicans are greatly exaggerated.

“If you look at the issues that define Rand Paul — for instance, on the NSA — it’s not at all clear that he’s playing nice-guy with the Republican leadership,” he said. “They generally disagree with him, but they, you know, they sort of go down to the Senate floor during the filibuster, hat in hand, to pretend that they’re with him.”

Pushing Cruz aside may be difficult, the conservative source said, for the establishment and Paul alike. To win the Iowa caucuses, Paul needs to win social conservatives who backed Rick Santorum over Ron Paul in 2016, which may be difficult because of his association with libertarians.

“I believe [Rand Paul] is very much pro-life and is very much in favor of traditional marriage,” the source said. “However, most people assume that he is truly like his father, even further libertarian, and most libertarians are pro-gay marriage and are pro-abortion. And so any comments that he makes that confirm those preconceived notions become very hard to move away from at a later time or to fix.”

Cruz, for his part, has found early success in appealing to Santorum voters, as the Dallas Morning News recently observed. As early as last summer, a former Santorum political hand accused Rand Paul's supporters of pushing the theory that the Texas senator isn't actually eligible for the presidency in an attempt to undercut his popularity with Christian conservatives in the state. Cruz, who was born in Canada to an American mother, is eligible.

And there is some indication that the rivalry between the senators themselves is growing, to judge from the recent dust-up over foreign policy.

“It used to be the dream team when the three of these guys, including [Utah Sen.] Mike Lee, would take on an issue together, because they all have different skill sets when it comes to organizing a majority coalition and, you know, Ted Cruz is a guy that throws a punch,” Kibbe said, after emphasizing the broad policy agreements between Cruz and Paul.

“I think the only dispute of any significance was the defund effort," he said. "But that was one fight.”

Paul's libertarian bent has definite advantages for his electoral prospects, though. His anti-NSA message earned a standing ovation from a crowd of students at the University of California-Berkeley -- hardly a friendly venue for Republicans.

He also holds positions that are out of step with law-and-order Republicans but perhaps appealing to traditional Democratic voters. For instance, Paul has denounced the way drug laws result in the disproportionate imprisonment of black Americans and called for a “21st-century civil rights agenda,” listing an array of policy ideas that don't fall neatly into one political category or another. The Republican National Committee, which has identified minority outreach as a critical need for the party, is happy to have Paul play a leading role in that effort.

Paul’s outreach hasn’t gone perfectly — he struggled to connect with a Howard University audience, for instance — but he's nonetheless road-testing a political message that would allow him to shift smoothly from a Republican primary to a general election campaign.

Before that happens, though, Tea Party activists may have to get used to watching two of their heroes fight for leadership of the conservatives and the Republican Party.

"I can't take it right now," Kremer said of the recent foreign policy spat between the Cruz and Paul. "We need to be focused on the Senate, and I don't like any friction between our guys up there. We have enough friction between the conservatives and the RINOs."