A reeling Hillary Clinton vowed to make a stand in Ohio and Texas primaries March 4. John McCain is already the GOP in-waiting.

But each has a lot riding Wisconsin primary Tuesday — and not, the New York Times observes, simply by winning or losing.

Clinton has not won a race since Super Tuesday, and needs a solid showing in Wisconsin - even in defeat - to stop the bleeding.

McCain has won the contests that matter most, but by narrow margins in some states that illustrate a rift with the Republican establishment.

He needs a win - a big win - to show the GOP is behind him and focus his full attention (and money) on a challenging fall campaign.

Must win by a lot, must not lose by a lot: John McCain and Hillary Clinton both need stronger numbers in Wisconsin than they got in Virginia.

Appearing in Texas as returns came in after last Tuesday’s defeats, Clinton seemed to be lowering expectations conceding Wisconsin already.

But for empirical and intangible reasons, she can’t. Another lopsided defeat puts her further behind in delegates, and absorbing another rout in a state with Hillary-friendly demographics has far-reaching effects.

Basically, a 60-40 loss makes it harder for Hillary Clinton to energize supporters and take the Ohio primary by a similar margin.

Thus, Clinton has been campaigning in Wisconsin personally, stepping up criticism of Barack Obama and running attack ads as well.

Polls show Obama leading, but not by much.

John McCain faces a different challenge in that a weakness in the heart of the party’s base is impeding his ability to focus on November.

That has raised the stakes in Wisconsin, where Mike Huckabee will enjoy a smaller base of conservative Christian support than in Virginia.

Without a big victory — double-digits and 50 percent-plus — McCain may be forced to use scarce capital during a protracted battle with Huckabee on March 4, when the former Arkansas governor is focusing on Texas.