MacLeod told supporters at her Ottawa campaign headquarters she would not have quit the race if Baird had not announced he was resigning as foreign affairs minister and soon would also quit his Ottawa West-Nepean seat in Parliament.
"I'm going to be brutally honest with you, no I wouldn't have. I'd still be in the race," she said. "That, coupled with the fact that Vic Fedeli had gotten out of the race, made it very clear that I had some very tough decisions to make."
MacLeod, who has a young daughter attending school in Ottawa, said she was getting a lot of "pressure" from constituents to "come back home" and run as a federal candidate.
It has been a "very intense" few days contemplating her future, added MacLeod, who insisted she still hasn't decided if she will seek Baird's seat once he officially resigns as an MP.
"The last 72 hours have changed my political reality," she said. "I'll let you know in a couple of weeks what I decide in terms of whether I'm going to pursue a federal career."
MacLeod's other decision was to throw her support behind perceived front-runner Christine Elliott, the deputy PC leader and widow of former finance minister Jim Flaherty, who was also endorsed by Fedeli when he withdrew on Wednesday.
Her move to abandon a leadership bid comes on the day candidates had to post $50,000 to stay in the race, which was one of the reasons Fedeli cited when he pulled out, but MacLeod insisted money was not the issue.
"We actually had to recall our $50,000 cheque for the deposit in the last 24 to 48 hours," she said.
PC party officials said the three remaining candidates all paid their deposits by Friday afternoon.
London-area MPP Monte McNaughton said he's the only real 'conservative' option in the race, insisting voters will always chose the Liberals if the PCs offer "Liberal-lite" alternatives like his rivals.
"It's now down to three candidates, the field is set, and I'm really excited about the momentum we are gaining across the province," McNaughton said in an interview. "We're signing up thousands of party members."
Barrie MP Patrick Brown, the only leadership hopeful who doesn't have a seat in the Ontario legislature, said he expected the race would come down to him and Elliott.
"It's going to be the same old top-down establishment party that my chief opponent is pitching, and I'm going to be pitching a vision of a party that is process driven and has a fresh renewal," Brown said in an interview. "We always thought it was going to be between us and Christine."
Progressive Conservatives across the province will be eligible to vote May 3 and May 7 for the leader to replace Tim Hudak, who resigned after the Tories' fourth consecutive election loss last June. The results will be announced May 9.
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