WATERLOO, Ont. — NDP Leader Thomas Mulcair was campaigning all over southwestern Ontario last week and at every day-ending rally, supporters were pretty much told Justin Trudeau was a coward.

In rallies in Scarborough, Hamilton, and Windsor, Mulcair was introduced by an MP or candidate who referred to the fact that only Mulcair was “standing up” against C-51, the controversial anti-terrorism bill the Conservatives introduced and the Liberals voted in favour of, even though Trudeau said he did not like parts of the bill.

Trudeau was never mentioned by name but everyone in the room knew exactly who was being called out for failing to stand up against what was described as a bill that was taking away civil liberties.

“I’m not afraid of Stephen Harper,” Mulcair told me during a whistlestop in a riding here where he hopes his party’s candidate can defeat an incumbent Conservative MP. “We said we would stand against [C-51] on principle and when that’s your conviction, you have to have the courage of your convictions.”

There, he did it again. Mulcair has courage. Trudeau does not. That’s the message.

Liberals finally, if tentatively, fired back this week, calling out Mulcair for his party’s irresponsible position that they would honour a referendum to separate from Canada with a bare minimum majority of 50 per cent plus one.

But who cares? No one but the last bushel of Gilles Duceppe supporters is going to be casting a ballot this fall on national unity.

Say what you want about Stephen Harper but on his watch, national unity/disunity is as dormant as its been in 60 years. And then the NDP went out and beat all of Duceppe’s fellow travellers at the ballot box in 2011.

But if the Liberals are looking for something a little stronger to push back at the NDP, they might pay a little attention to some of the things Mulcair was saying on his southern Ontario swing.

For example, as Windsor Star columnist Anne Jarvis wrote Friday, Mulcair was vague and possibly contradictory in statements he made in her city about support for the auto sector. She was right — and others would be too — to call for a little more clarity on NDP plans.

And then there’s Mulcair’s plan to restore home mail delivery. When Mulcair makes this commitment in his stump speech, it is the single most popular line of the night, the one that had the crowd in Hamilton and London on their feet for a standing ovation.

Canada Post is a Crown corporation that is making a profit precisely because it has cut costs, like home mail delivery. Would his government underwrite this money-losing home deliver and, in this day and e-age, unnecessary service?

And then, on Friday, there was what appeared to be a flip-flop on the gun registry. “We have no intention of bringing back a gun registry,” Mulcair told reporters in London, Ont. “Now I do want to make sure our police have the tools necessary … but the NDP has no intention whatsoever of bringing back the gun registry.”

That will surprise some urban progressive voters who might have believed Mulcair when he vowed in December that a registry, albeit a different one than the Liberal version, was coming back.

“We will bring in something that allows the police to track every gun in Canada. That’s an obligation we intend to respect,” Mulcair said outside the House of Commons on Dec. 3, 2014.

When the Liberals won their last majority government, 15 years ago in the election of 2000, this whole region west of Highway 6 down to Windsor, went all red. Nowadays, there’s just one dot of red, in Guelph, a handful of orange blips and the rest is Tory blue.

New Democrats are not supposed to be the alternative to the Conservatives for dairy farmers in nearby Stratford, tool-and-die makers in Chatham, or the chamber of commerce type in Brantford. That’s what Liberals are for.

But it appears Mulcair and the NDP are fast becoming the go-to choice for the millions of Canadians who absolutely will not vote Conservative.

At lunchtime in Stratford on Friday, 200 people crowded into a pub just to get selfies with Mulcair. A Thursday afternoon whistlestop at a Sarnia microbrewery drew 150 cheering supporters.

And each night he spoke to crowds of more than 400. In the middle of summer. Three months before an election. I expect those crowds to grow — unless one of his opponents wants to do something about it.