This afternoon, the House of Representatives will vote on a measure to restrict funding for the Libya operation — a move intended as a rebuke of the President for refusing to seek Congressional authorization for the war.

A number of folks have raised questions about the motives of House Republicans in pursuing this vote. But that isn’t really the key thing to be watching here.

Rather, what really bears watching is how many House Democrats support this measure. If enough Dems vote for it to create a sense that it has significant bipartisan support — which seems very possible — it will stand as an important statement of discomfort with Obama’s continued insistence that he doesn’t need Congressional authorization to continue the war.

In a key development, a source in House Minority Whip Steny Hoyer’s office confirms that House Dem leaders — who oppose the measure — are not urging rank and file Dems to vote against it. Instead, while making their own feelings known, they are telling members to vote their consciences.

Some opponents of Obama’s Libya operation are interpreting this as a sign that Dem leaders think it likely that there will be a significant number of defections against the President, and don’t want to be seen whipping for a losing vote.

In another interesting development, Dem Rep. Dennis Kucinich is urging colleagues to vote for this initiative, even though it’s the work of the GOP leadership — another sign of the bipartisan opposition to the President’s refusal to seek Congressional authorization. In a letter to House Dem colleagues this morning about the GOP proposal, Kucinich wrote: “If his authority is not limited immediately, the President could easily escalate the war, using the blank check he has written for himself by declaring he doesn’t need authorization or funding from Congress for the war in Libya. Vote YES.”

Moments ago, the House just voted on another, separate measure — one to authorize the continuation of the war without funding. It was defeated resoundingly. But that measure was never going to pass — it was pure theater. The more important vote is the upcoming one on whether to restrict the war’s funding.

To be clear, even if the measure passes this afternoon, it won’t have a real-world impact: It will never pass the Dem-controlled Senate, which may not even vote on it. Nonetheless, if dozens of House Dems vote today to restrict Libya war funding, it will stand as a significant statement of protest against a war policy that, as Bruce Ackerman puts it, risks creating a troubling precedent for future presidents to wage war at their convenience, with no regard for pesky checks and balances.

UPDATE: Okay, so the measure just went down to defeat, 180-238. But some three dozen Dems voted Yes — meaning three-dozen Dems voted to defund the war. That might not be quite as strong a showing as those who want to challenge Obama’s refusal to seek Congressional authorization may have hoped for. But it’s still a noteworthy defection among Dems.