Republican Senate candidate Roy Moore, right, and former White House chief strategist Stephen K. Bannon shake hands during a recent campaign event in Fairhope, Ala. (Jonathan Bachman/Reuters)

Roy Moore hasn’t spent much time lately trying to make friends with his potential Republican colleagues in the Senate. When a series of women publicly accused the 70-year-old Moore last month of predatory sexual behavior and assault when they were teenagers and he was in his 30s, several Senate Republicans rescinded their endorsements. Others urged Moore to end his candidacy — and even suggested that, if elected, he should be expelled from Congress.

Moore responded with defiance, denouncing Senate Majority Leader Mitch McConnell (R-Ky.) and his “cronies” for trying to “steal this election from the people of Alabama.” When Sen. Jeff Flake (R-Ariz.) criticized Moore for damaging the reputation of the Republican Party, a Moore campaign spokesperson fired back that Flake was one of the GOP’s “agents of destruction” who “assassinate conservatives like Roy Moore so they can work with the liberal elite to protect their big government trough.”

But Moore responded very differently when Fox News Channel host Sean Hannity expressed his concerns about the accusations. On Nov. 14, Hannity called on Moore to “immediately and fully come up with a satisfactory explanation” for the allegations or “get out of this race.” Hannity gave the candidate “24 hours” to respond.

The Moore campaign scrambled to satisfy Hannity’s demand. The next day, Moore released an open letter personally addressed to Hannity that sharply denied the accusations and said he was a victim of a “desperate attempt” by the “liberal media” to “smear my character and defeat my campaign.” That argument was custom-built to appeal to the Fox host, who frequently argues that mainstream media sources are biased against conservatives. Hannity praised Moore for answering and dropped his ultimatum, concluding that Moore’s innocence should be judged by the voters of Alabama.

Why the sharp contrast between the deference Moore showed Hannity and his open contempt toward McConnell?

As Moore recognizes, power has shifted within the Republican Party. Moore is responding not to those who formally lead the party but to the real source of his potential votes.

Supporters of Alabama Republican Senate candidate Roy Moore turned out at his final campaign rally on Dec. 11 and explained why they continued to stand behind him despite the allegations of sexual harassment. (Jordan Frasier/The Washington Post)

What makes up a political party?

For many years, most political scientists followed the lead of the eminent V.O. Key Jr. in conceptualizing each U.S. party as a three-legged stool composed of voters, politicians (and other government officials), and officers of the national, state and local party committees. More recently, however, many scholars have come to accept a different model of American politics in which elected officials, candidates, committee members and voters share control of the two major parties with a dense web of other individuals and groups that do not hold formal office but nevertheless significantly influence party affairs.

In this new view, Democrats and Republicans have each developed an “extended party network” that connects politicians and citizens to a wide variety of other powerful actors that include interest group organizations, financial donors, policy experts, strategists and consultants, and — especially for Republicans — media sources. Scholars of party networks argue that these other figures are sufficiently integrated into the organizations of each party that they should properly be considered components of the party itself — especially because they can sometimes pressure the titular “leaders” of their party to satisfy their demands.

Hannity has never held elective office, does not work in government and does not serve on a party committee. In fact, as of 2014, Hannity was not even registered as a Republican voter. But Moore showed that he thinks Hannity holds more sway over Alabama Republican voters — and his own electoral fortunes — than the party’s top senator. For political scientists and other students of American politics, treating Hannity as a party leader in his own right — and one with no small degree of influence in today’s GOP — seems more appropriate than restricting our definition of the party organization to its formal apparatus alone.

Especially within the Republican Party, power seems to be shifting away from officeholders and toward unelected authorities, most notably the conservative media. Over the past decade, insurgent candidates — such as Moore, and President Trump before him — who lacked strong support from fellow Republican politicians have nevertheless repeatedly beaten “establishment” rivals in nomination battles, fueled by the outspoken backing of radio, TV and Internet personalities on the right.

So who are the new Republican power brokers?

Of course, Hannity and his Fox News colleagues are prominent sources of influence. Another is Stephen K. Bannon, who returned to his position as chairman of Breitbart News in August after serving in the Trump campaign and administration. Bannon, now trying to consolidate power within the GOP from his perch at Breitbart, campaigned for Moore during his successful primary race against appointed incumbent Luther Strange. And Bannon has remained a strong supporter despite the recent controversies.

Conservative Christian authorities are another important element of the extended Republican Party network, especially in the South. One Moore radio ad features a testimonial from James Dobson of Focus on the Family. Evangelist Franklin Graham, the son of Billy Graham, has actively defended Moore in the media. It’s true that some Alabama pastors — even among those who previously said they supported Moore — have quietly backed away from him since the accusations surfaced. But few Alabama white evangelical leaders have publicly denounced Moore or thrown their support behind his Democratic opponent.

Sen. Richard C. Shelby (R-Ala.) and politicians from both parties on Dec. 10 weighed in on the accusations of sexual misconduct against Roy Moore, the Republican nominee for U.S. Senate in Alabama. (Bastien Inzaurralde/The Washington Post)

In politics, holding the title of “leader” is one thing; actually enjoying the power to lead can be quite another. For several weeks, McConnell fruitlessly called on Moore to abandon his campaign for the Senate. But with opinion polls giving Moore a good chance of victory, and with Trump expressing strong support for Moore, McConnell tacitly admitted defeat.

“I think that at this point we’re just going to let the people of Alabama make their decision,” McConnell told a reporter Dec. 3. He sounded an awful lot like Sean Hannity.

David A. Hopkins is an associate professor of political science at Boston College. His latest book is “Red Fighting Blue: How Geography and Electoral Rules Polarize American Politics” (Cambridge University Press, 2017). He blogs about U.S. politics at HonestGraft.com.