Vice President Biden, right, shakes hands with Vice President-elect Mike Pence after their meeting and lunch at the Naval Observatory in Washington on Nov. 16. (Gary Cameron/Reuters)

Gov. Mike Pence has been very active since the election last month. He’s heading Donald Trump’s presidential transition, meeting with prospective administration officials and influencing Cabinet selections, speaking with members of Congress, appearing on TV talk shows and outlining policy for Trump’s first term.

This burst of activity has prompted predictions that Pence will be an unusually powerful vice president. Perhaps, but it’s too soon to tell. Vice-presidential influence depends on institutional arrangements, circumstance and personal relationships. Let’s consider how these might — or might not — lead to a historic vice presidency.

The institution of vice president has changed over time. But then, Trump hasn’t been respecting other institutional precedents.

For most of American history, vice presidents presided over the Senate and did little else. The office moved to the executive branch in the 1950s, but not until President Jimmy Carter’s presidency did the VP step into the president’s inner White House circle.

Carter and Walter F. Mondale redefined the position as that of a close presidential adviser and troubleshooter, adding resources to support those roles. That’s when vice presidents became integral parts of the presidency rather than just potential successors.

That’s stayed true over the past 10 presidential terms, from Carter-Mondale to Obama-Biden. The last six presidencies have included an engaged vice president who spent time with the president and other senior advisers and handled major assignments — and firmed up a bipartisan consensus that presidents could govern better with a powerful, able and loyal vice president.

Pence will therefore step into an ascending office. But Trump has ignored other accepted conventions — such as the expectation that candidates disclose their tax returns, that the president-elect hold news conferences, and, perhaps, that presidents and vice presidents liquidate holdings to mitigate conflicts of interest.

Having a powerful vice president serves the president’s self-interest, and so might well survive. But this precedent would be more secure with a more conventional president.

A vice president with more government experience than the chief can be especially influential — but it takes more than that.

Some recent vice presidents have owed their early influence partly to their far greater experience in Washington. Among the last six vice presidents, the exception would be Dan Quayle, who served under the immensely experienced George H.W. Bush. The elder Bush had served two terms as Reagan’s vice president and before that as a member of Congress, chaired the Republican National Committee, directed the CIA and held senior diplomatic posts at the United Nations and in China.

This “presidential-outsider/vice-presidential insider” disparity is especially pronounced in the Trump administration. Pence’s experience as a member of Congress gives him not just experience but also friendships with many Republican members of Congress who opposed or were unenthusiastic about Trump’s candidacy.

But the “outsider-insider” differential isn’t the real source of vice-presidential influence. Quayle didn’t benefit from that advantage but made important contributions to the first Bush administration as a political and legislative adviser and operator, liaison to conservatives, diplomat to Latin America and Asia and chair of Bush’s competitiveness council. Other vice presidents have helped even in areas where the president was skilled and engaged — as when Al Gore worked on Bill Clinton’s “reinventing government” initiative and with Russia.

The “White House vice presidency” assumes that any president needs high-level help. Vice-presidential influence depends on the quality of the vice president’s advice and his skill at handling assignments, and not on superior experience to the president. For instance, Joe Biden’s vice presidency has been highly successful because he has done his job very well, not simply because he is experienced and liked on the Hill and abroad. By contrast, Dick Cheney saw his influence decline as his advice regarding Iraq proved misguided and as his handling of the reauthorization of the warrantless surveillance program in spring 2004 almost resulted in the election-year resignations of a slew of senior Justice Department officials in protest.

Pence’s influence will hinge not so much on his background and relationships but on his job performance.

What’s the strength of the relationship between the president and vice president?

Any vice president’s power comes from a strong relationship with the president. The question is, does trust develop and is it sustained over time?

It’s hard to predict which pairs will hit it off and remain close, and which relationships will sour. Clinton and Gore were Southern baby boomers and Democratic centrists — but became estranged after the president’s sex scandal and as Gore sought the presidency. George W. Bush and Dick Cheney claimed that Cheney’s lack of presidential ambitions gave them a common political agenda, but they grew more distant in the second term.

By contrast, Ronald Reagan and Bush overcame initial misgivings to have a warm relationship. Generational and stylistic differences did not stop the celebrated Obama and Biden bromance.

It helps if the president isn’t threatened by a vice president’s favorable press. Presidents like Lyndon Johnson and Richard Nixon might have tormented almost any vice president. But Gerald Ford’s affection for Nelson A. Rockefeller did not spare Rockefeller from an unpleasant vice presidency or from being dumped once he became a political liability.

How the president governs also makes a difference. Does the vice president meet privately on a regular basis with the president for confidential exchanges? If so, the VP can protect his position by remaining silent at meetings when leakers are present. Is the president’s decision-making style centralized or diffused? If the former, a vice president with access becomes even more important to those outside the room.

But if the president delegates decisions to others or favors large decision-making sessions, the vice president may hold fewer cards. Vice-presidential peril increases where the president surrounds himself with antagonistic and sharp-knifed factions, especially when the VP becomes a target.

Vice presidents as defenders of the realm

Finally, vice presidents are expected to defend the president. That role has costs, as Hubert Humphrey learned. Some vice presidents have set limits. Pence declined to defend Trump over the Access Hollywood recording. He supported some Republican politicians whom Trump refused to endorse. And he accepted the statement from the “Hamilton” cast that disturbed Trump.

On the other hand, more recently, he refused to distance himself from Trump’s unsupported assertion that Hillary Clinton’s popular vote margin rested on illegal votes.

Trump’s tendency to offend different groups might mean Pence regularly has to decide whether to preserve his own credibility or show loyalty to the president.

So what does all this mean for Pence’s power?

Pence has had a very good month. But transitioning is not governing. Many situations ahead will test his skill, wisdom and ability to forge and sustain strong relationships with Trump and his administration. How well he navigates those challenges over time will determine the success of his vice presidency.

Joel K. Goldstein, the Vincent C. Immel Professor of Law at Saint Louis University School of Law, is the author most recently of “The White House Vice Presidency: The Path to Significance, Mondale to Biden.”