On Sunday, the Manchester Union-Leader, the leading conservative newspaper in New Hampshire, endorsed John McCain for President. Their editorial is here. The paper has been a frequent critic of McCain in recent years, for the same reasons he has trouble with conservatives generally: campaign finance reform, the "Gang of 14," the immigration bill. The endorsement came, therefore, as something of a surprise - a most welcome one for McCain, who has been steadily battling back into contention, especially in New Hampshire, after having been written off by most pundits - myself included - before summer's greens began to change colors.

Endorsements aren't what they once were, and they were never as important as the endorsers and endorsees made them out to be. But this is still an influential newspaper among New Hampshire conservatives, and one which has not been kind to McCain in the recent past. It doesn't hurt. While the Real Clear Politics average of recent polls has McCain in third place with 15.5% behind Romney's 33.8% (and Giuliani's 18.5%), one poll has him within eight points of the leader. He won the state with a majority in 2000, albeit aided by Democratic and independent votes which may not be there this cycle due to the competitive race on the other side.

Romney and Giuliani are experiencing their own problems right now, taking their campaigns "off message." Thompson isn't making a bid for the state, and Huckabee probably won't do well there either, even if he wins Iowa, due to his history of raising taxes. The door is open.

A win in NH could give McCain enough momentum to contest South Carolina, where he is currently running fifth - but only 8.7% behind Romney in first - in the RCP averages. McCain took 42% of the vote in SC in 2000, losing to Bush in a two-man race. The door is open.

Romney's whole strategy is predicated on winning Iowa and New Hampshire. If he wins neither, he is done; if he wins only one by a small margin, he is badly wounded. Giuliani isn't positioned well to win until Florida - his strategy focuses on the bigger states, but their later voting (except for Florida) gives opportunity to the others in the smaller, earlier states. The door is open.

Envisioning an outright McCain victory still requires imagination, but seeing a race where no candidate goes to the convention with a majority does not. In such an event, McCain would be the logical compromise candidate, as the only one with the stature to both unite a fractured party and to beat the Democratic nominee, whoever she is.