Ad Hawk is an occasional series evaluating the effectiveness of political advertising.

The 2015 federal election is in the home stretch, so cue the attack ads.

Liberal Leader Justin Trudeau is the focus of two new attack ads from the Conservative Party, providing solid evidence that Conservative Leader Stephen Harper's campaign brain trust has concluded that this election has become a two-horse race. Leader Tom Mulcair and his New Democrats are nowhere to be found in either Conservative ad.

Conservative ad No. 1: 'Economically Clueless'

Note: Ads are produced by the candidates, their parties or their agents. They are embedded here for informational purposes only and their placement does not constitute an endorsement by CBC News.

What's the message?

Hard-working Canadians risk losing everything, the ad suggests, if they elect Trudeau as prime minister. The ad quotes a newspaper columnist who referred to Trudeau as "economically clueless" and argues that Trudeau hasn't "thought through" the Liberal platform he is advocating.

The ad — which features several shots of Trudeau and none of Harper — sets out to frighten Canadians by warning that Trudeau would incur a $10-billion deficit "and a $1,000 tax hike on the typical worker" — the latter referring to a payroll tax.

"Families: Cancel child-care cheques" is the next headline, with the word "cancel" in giant letters set over a picture of a cute baby playing with toys. And this is "all to pay for his out-of-control spending," the ad argues, showing a headline on screen of "$146 billion in new spending." The ad ends with the now familiar kicker: "Justin, he's just not ready and you'll pay for it. We'll all pay for it."

Why now?

The NDP's decline in public opinion polls might accurately reflect what the Conservatives are seeing in their own, private polling research — namely that the Oct. 19 election has come down to a choice between Trudeau and Harper. Hence the no-holds-barred attack on the Liberal leader.

Kernel of truth here?

The Conservatives are careful to have just enough truth to make their claims. On the one hand, the Liberals will cancel the Conservatives' child care cheques — but for Canadians earning less than $150,000, they are proposing to replace them with richer, tax-free monthly benefits. The $1,000 payroll tax can only refer to the Liberals' support for a supplemental pension plan, the details of which haven't been worked out. And so on.

What score or rating would you give?

This ad scores a 2/5 because it is too much a cliché of a political attack ad – almost a parody version. Voters are more sophisticated about these kinds of negative ads than ever before. They are seeking authenticity. And they won't find it here.

Conservative ad No. 2: 'Canada faces a big decision'

What's the message?

This ad argues that "it's decision time — Liberal or Conservative," and then places on screen a hand-written chart, with the left-hand column titled "Justin" and the right-hand column titled "Harper."

The ad fills in the "Justin" column first with the same allegations as the ad above, except for the addition of an unspecified small-business tax hike. The "Harper" column is filled in with "protect our economy with a balanced budget," and "a tax cut on your paycheque," specified on screen as a 20 per cent payroll tax cut, and an unspecified tax cut for small business.

"Higher taxes with Justin. Lower taxes with Harper," the announcer states. "In an election this close, there's a lot at stake for you and your family."

Why now?

The motivation behind this ad appears to be as described above, to generate a clear contrast between Liberal and Conservative platforms and leaders.

Kernel of truth here?

Again, many of the suggestions about the Liberal economic plan used in the ad above are repeated here. The Liberals might argue it amounts to a distortion of the facts, but twisting the truth is traditionally what attack ads are all about.

What score or rating would you give?

This ad scores a 3/5 because it is far less clichéd than the first ad above. The theme is simple for most Canadians to grasp — the clear choice they have to make. In that sense, setting aside the facts, it works.

Bill Walker is president of MidtownPR. He was previously the Ottawa and Washington bureau chief of the Toronto Star. His assessment is part of an occasional series evaluating the effectiveness of political advertising.