KEVIN O’CONNOR tried to pull off a highwire act during Monday’s night’s debate against Sen. Ed Markey, portraying himself as both a Gov. Charlie Baker and a President Trump Republican.

It was not an easy sell during the GBH debate as Markey at every turn sought to portray O’Connor as a surrogate for Donald Trump, who polls show is not well liked in Massachusetts. “You know you’re a Donald Trump Republican when you don’t wear a mask yourself in public,” said Markey to O’Connor. Markey then described Trump’s handling of the coronavirus pandemic as “criminally negligent.”

O’Connor, in response to questions, showed he differs from Trump on a number of issues, including supporting the DACA immigration program, which stands for deferred action for childhood arrivals; acknowledging climate change; seeking net zero greenhouse gas emissions by 2050; and backing health care the way it is provided in Massachusetts.

“For all Sen. Markey wants to run against President Trump, I am running as a Kevin O’Connor Republican,” O’Connor said, noting his positions are largely consistent with those of the middle-of-the-road Baker, who, he said, is supporting him and not Markey.

But at the very end of the hour-long debate, cohost Margery Eagan brought the debate back to Trump, asking O’Connor why he was voting for the president if he disagreed with him on so many issues.

“Because President Trump represents the best opportunity for us to have safe neighborhoods, not open border, sanctuary states, not defunding and disarming of the police the way Sen. Markey advocates. He offers the better alternative, the better choice in terms of restoring our economy,” he said.

Just hours before the GBH debate, the TV station announced the two candidates would appear not together as planned but separated in different studios. When O’Connor complained on-air about the change, GBH cohost Jim Braude apologized but said the station believed the world changed on Friday, when Trump’s COVID-19 diagnosis became public.

Markey, who polls show has a strong lead and a sizeable campaign cash advantage in his race against O’Connor, has agreed to just one debate with his Republican challenger. Even that limited public exposure for O’Connor was undermined somewhat when COVID-19 prompted the NFL to move the Patriots-Chief game from Sunday to Monday night at the same time the debate was being held.

Markey’s primary challenger, Joe Kennedy III, was wary of challenging the senator on policy issues for fear of offending the Democratic base in Massachusetts. O’Connor, however, showed no such reluctance. He went after Markey repeatedly for being a lefty extremist who is out of step with his own party.

O’Connor, an attorney from Dover, dismissed the $2,000-a-month payment Markey wants the country to make to every person in the nation as a $96,000-a-year “free-lunch program” that would bankrupt future generations.

He criticized Markey for being an extremist on abortion, on the Green New Deal, on Medicare for All, and on the elimination of private health insurance.

“He’s outside the mainstream of his whole party,” O’Connor said.