If I want to raise a conservative friend’s blood pressure these days, I’ll ask him what he thinks about North Carolina’s senior U.S. senator, Richard Burr.

Many are angry at Burr. Most disagree emphatically with his Feb. 13 vote to convict former President Donald Trump in his second impeachment trial. Those who support Burr’s impeachment vote are likely to keep that information to themselves.

No one can dispute that Burr is paying a political price for his action. That includes an official vote of censure from the N.C. Republican Party’s Central Committee. The price likely would be much higher had Burr not already announced retirement plans. He will leave his Senate seat at the end of 2022.

Critics tend to focus on Burr’s perceived betrayal of Trump in particular and the Republican Party generally. Why would the senator fail to back a president from his own party?

To find an answer, it might make sense to examine Burr’s official statement about his vote; “The evidence is compelling that President Trump is guilty of inciting an insurrection against a coequal branch of government.”

One could devote a full column to testing the assertion that the evidence against Trump was compelling. There’s also plenty of room for disagreement about whether Trump’s words and actions on Jan. 6 met the historical legal standard for “inciting an insurrection.”

Of more interest to this observer are the words “coequal branch of government.” That phrase likely helps explain a key basis for Burr’s vote.

Remember that Burr is serving his 17th year In Congress’ upper chamber. Before joining the U.S. Senate, he spent a full decade representing a Triad-based district in the U.S. House of Representatives. For more than a quarter century, then, Burr has been a creature of the U.S. Capitol, home of the federal government’s legislative branch.

That fact alone will be enough for some to brand Burr a villain. But it also explains why he might shudder at the prospect of a president — any president — encouraging an angry crowd outside the Capitol. That’s especially true if that crowd wants to block the legislative branch from doing its job.

It’s possible that Burr’s vote to convict Trump also represented a vote to support his “coequal” branch of government. Our constitutional system requires the legislative branch, Congress, to conduct its business free of threats of violence. If a mob can stop congressional work in its tracks once, there’s no guarantee that it couldn’t happen again.

Burr undoubtedly knew that a vote to support Congress’ constitutional role would be viewed primarily as a vote against Trump. He also should have known that the vote would carry a hefty political price. Just look at recent history involving his home-state colleague in the U.S. Senate.

In February 2019 the Washington Post published a widely read column. Sen. Thom Tillis explained in print why he opposed Trump’s plan to use national emergency powers to free up money for his southern border wall.

“As a U.S. senator, I cannot justify providing the executive with more ways to bypass Congress,” Tillis wrote. “As a conservative, I cannot endorse a precedent that I know future left-wing presidents will exploit to advance radical policies that will erode economic and individual freedoms.”

Tillis made clear in the same column that he supported Trump’s border strategy, as he had supported most of the Republican president’s policies over more than two years of working together. Tillis’ objection focused on the potential weakening of congressional authority.

The caveats made no difference. Most Republicans bashed Tillis for failing to stand with Trump. Some openly floated the idea of recruiting other members of the state’s congressional delegation to run against him in a 2020 primary election.

When the issue came to a vote less than three weeks after the column appeared, Tillis changed his mind. He supported Trump’s emergency order.

The senator justified the switch by saying White House officials had agreed to help him reform federal law. The Article One Act Tillis co-sponsored would have given Congress more oversight over national emergencies lasting longer than 30 days.

“That this president is prepared to transfer power back to the Article I branch [Congress] by his statements either publicly or through his administration is extraordinary,” Tillis said.

Yet the debate over Congress’ constitutional role and the importance of checks and balances attracted little attention. Instead, headlines documented Tillis’ “flipflop.” First, he was against Trump. Then he was for Trump. Where did he really stand?

The Post piece did play a role in generating a credible primary challenge for Tillis. He survived that fight and squeaked through the general election, after spending much of the year running behind other Republican candidates in statewide polls.

Tillis’ colleague faces no such political threat in 2022. Regardless of Burr’s impeachment vote, someone else will be sitting in his Senate office after the next election. In the meantime, Burr likely faces a serious case of GOP mistrust and anger.

Political observers can learn lessons from both Tillis’s 2019 national emergency vote and Burr’s 2021 impeachment decision. It’s possible to take a principled stand for Congress’ “coequal” role and the Constitution’s checks and balances. Those who take that stand should be ready to pay a political price.

Mitch Kokai is senior political analyst for the John Locke Foundation.