This time a week ago, the nomination of Larry Summers to be the next chairman of the Federal Reserve seemed like a near-certainty. The signals out of the White House were that the president had largely made up his mind and that the administration was biding its time on the details of a rollout. Now, it is becoming clearer the type of fight President Obama will face, including within his own party, if he moves forward.

Earlier in the week, the Wall Street Journal reported that three key Democratic senators on the Banking Committee are likely to oppose a Summers nomination, namely Sherrod Brown (Ohio), Elizabeth Warren (Mass.) and Jeff Merkley (Ore.). Bloomberg on Friday confirmed Brown's likely "no" vote, via his spokesperson. Reuters on Friday reported that a fourth Democrat on the committee, Jon Tester of Montana, is a "no," citing his spokesperson.

Remember, the Summers nomination hasn't even been announced yet. Democratic senators could easily say "no comment." The reason so many are commenting is to lay down a public message for Obama: Nominate Summers, and you'll have a real fight on your hands.

Just doing the math, Democrats have a 12 to 10 majority on the Senate Banking Committee, which would need to clear any nomination, and the four probable defections mean that Obama would need four Republican votes out of the 10 on the banking committee just to get a Summers nomination to the floor of the Senate. [Updated: We originally wrote that in this scenario there would need to be only three Republican votes; we had done the math wrong.]

Moreover, the nomination will then hit the floor, where it will almost certainly need to pass a 60-vote threshold. Losing four Democrats — at least — means winning the votes of 10 Republicans. And Republicans have little desire to make life easy for the president.

While some may view Summers, privately at least, as more likely to be tough on inflation and judicious in regulating banks than the likely No. 2 candidate, Janet Yellen, they have no real interest to voting to confirm a former Obama White House aide who was a crucial engineer of the 2009 fiscal stimulus. It's more likely that they'll try and turn the Summers nomination into a referendum on Obama's management of the economy — and once that happens, few if any Republicans will find themselves able to vote "aye."

Meanwhile, the National Journal — which sits in almost every Hill office — devoted its latest cover to the Summers nomination. Here it is:

Matt Stoller
(Via Matt Stoller)

The question for the president will be this: Is he ready for a fight? And how much political capital is he willing to expend, and how many arms will he twist, to get Summers into the big job at the Federal Reserve? Because if he goes through with the nomination, it looks after this week like it will be the toughest confirmation battle for a Fed chair on record.