Vice presidents matter.

Thomas Jefferson, Teddy Roosevelt, Harry Truman, Lyndon Johnson, and George H. W. Bush, among others, were vice presidents before they were presidents.

We have had some notable disappointments as vice president. Andrew Johnson, who was Abraham Lincoln’s inadequate successor, came within one vote of being impeached. Spiro Agnew, who almost became Richard Nixon’s successor as president, resigned in a bribery scandal.

And there have been poorly qualified vice-presidential candidates such as Sarah Palin (2008) and John Edwards (2004).

This past Tuesday night, the telegenic and blue-eyed Yale-educated J. D. Vance made a better case for Trumpism than Republican presidential candidate Donald Trump has done.

And Vance, the 2024 Republican vice-presidential nominee running on the same ticket with Trump, did it in a cordial and civil way without mean-spirited insults.

Vance had become relatively unpopular this summer for his unacceptable comments on “childless cat ladies” and illegal immigrants eating cats and dogs in Vance’s home state of Ohio. Vance also had made derogatory comments about the military service claims of his debate opponent, Tim Walz.

Walz is the Democratic candidate for vice president running with Democratic presidential candidate Kamala Harris.

But it was a focused, confident, and charming J. D Vance that came to last Tuesday’s vice-presidential debate to talk policy. He agreed that his Republican Party must do a better job of earning the trust of women. He acknowledged more needs to be done for healthcare, housing, and even climate change.

Vance , in contrast to his persona on the campaign trail, presented himself as a moderate waiting to work with Democrats to find acceptable solutions to a variety of problems.

He went to great lengths to defend Trump’s previous presidency. He did it in an understated and soft-spoken way.

Vance misrepresented the facts with deceptively cunning words, claiming that Trump saved Obamacare (Trump repeatedly worked to repeal it) and that Trump peacefully transferred power to incoming president Joe Biden in January of 2021 (there was a Trump-inspired riot at the U.S. Capitol building).

J. D. Vance performed well enough to push up his “favorability” ratings and his chances of playing a major role in a post-Trump Republican Party.

Minnesota Governor Tim Walz was initially nervous and a bit wobbly, yet he was a more than adequate defender of Democratic Party presidential nominee Kamala Harris. He failed to give forthright answers on a few occasions, yet became stronger as the debate went on.

The folksy Walz used several examples of policy progress on housing, crime, and health care from his experience in Minnesota. He also made relatively strong cases for a woman’s right to choose (an abortion) and for the bipartisan immigration reform legislation that Trump worked to defeat.

Walz made Vance embarrassingly uncomfortable when Vance had to defend Trump’s long standing but unfounded claims that Trump won the 2020 presidential election.

Tim Walz also scored some points by emphasizing how President Trump’s tax cuts mainly helped the rich. Walz claimed that Trump has apparently not paid federal taxes for several years. Walz further explained that Trump’s tax cuts were a major reason our debt has been soaring in recent years. Biden program have obviously added to this as well.

Unfortunately, this debate failed to press the candidates over how they would bring down the soaring National Debt. The Ukrainian-Russian war also was not discussed or debated.

Viewer and news commentator reactions suggested that Vance won on performance and style. Governor Walz, however, with just a couple of exceptions, held his own and did his job.

Both vice presidential candidates, Vance and Walz, were advantaged compared to presidential candidates Trump and Harris because they did not have to criticize each other directly. They mainly criticized the two presidential candidates.

Vance’s most telling criticism of Kamala Harris was the Biden-Harris failure to adequately control illegal immigration at the southern border.

Walz’s most politically effective criticisms of Vance dealt with abortion, healthcare and childcare.

Vance was the less popular candidate going into this debate. But he was also expected to be the better debater. He proved himself an effective communicator, more effective than his running mate, Donald Trump.

Tim Walz gamely defended Kamala Harris and the Democratic Platform. He is a political veteran with eight election victories (for U.S. representative and governor) in Minnesota. He was able to call on his congressional and gubernatorial experience and, though he may have come across as a little less confident than Vance, he showed that he was no rookie at politics.

Walz made it clear he understands American values and American concerns.

Some Democrats and news commentators believe that Pennsylvania Governor Josh Shapiro or California Governor Gavin Newsom would have been more effective Democratic Party debaters than Tim Walz — and they are probably right.

On the other hand, some viewers would prefer Vance and Walz to be at the top of their tickets as the presidential candidates. Initial polls gave both Vance and Walz positive ratings for looking presidential.

The debate probably did not change the overall dynamics of this highly contested and close presidential election.

But it was an important debate. Vice presidents, especially in recent generations, are almost always key advisers to their presidents and play a major role in recruiting top political appointees.

Their views can carry considerable weight in crisis decision making.

Vice President Walter Mondale played an important role under President Jimmy Carter. Vice President Joe Biden’s expertise helped President Barack Obama.

Vice President Mike Pence, as we now know, played a crucial role in upholding the Constitution in the final days of the Trump presidency.

Vice presidents can matter. Two cheers for Vance and Walz. They did the best job they could given the challenges they had of supporting presidential candidates and political parties that are not especially popular.

Two cheers also for CBS and the debate moderators as well. They helped to stage a memorable debate, a debate that served the public interest.

Walz was proud to say that the Harris-Walz ticket had a broad coalition behind it. Support ranges from liberal Bernie Sanders to conservative Republican Dick Cheney, a former vice president. Also supporting Harris-Walz is popular entertainer Taylor Swift.

Vance, who had less to work with on this front, lamely said he was proud to work alongside former Democrats Robert F. Kennedy, Jr. and Tulsi Gabbard.

The debate this week was watched by at least 43 million viewers — about 20 percent less than watched the Kamala Harris — Mike Pence debate four years ago.

Tom Cronin and Bob Loevy are commentators who write about Colorado and national politics.