Senate Minority Leader Mitch McConnell (R.-Ky.) can’t seem to catch a break. His poll numbers are down at home and his normally reliable deputy in the Senate is taking shots at him. Those two factors are shaping up to be important factors surrounding this week’s vote on a watered-down ethics reform bill.

As I reported earlier this week, two conservative senators, Tom Coburn (R.-Okla.) and Jim DeMint (R.-S.C.), are livid that Senate Majority Leader Harry Reid (D.-Nev.) gutted the earmark reform language in the bill. Coburn’s office released a detailed chart on Tuesday showing exactly what had been changed by Reid behind closed doors. And today DeMint’s office released a Congressional Research Service report that confirms the bill will not ensure complete earmark disclosure.

The mini-revolt stirred up by Coburn and DeMint hasn’t gone unnoticed among Republican leaders. In fact, the man whose quote adorns the Porkbusters website, Minority Whip Trent Lott, has sided them. But Lott also took it a step further and criticized McConnell in today’s edition of National Journal’s CongressDailyAM:

Asked whether Republicans could muster the votes to block cloture on the lobby bill, Lott seemed to suggest Minority Leader McConnell would not take a strong stance leading Republican opposition to the bill.

“After the exhibition I saw on immigration, I don’t suspect there’s going to be a lot of strength and dynamic leadership here [to oppose the lobbying reform legislation], but we’ll see,” he said, referring to GOP criticisms of McConnell’s lack of visibility during the final days of the unsuccessful immigration debate in June.

Republican aides privately criticized McConnell for putting his re-election concerns before the leadership needs of his party; the proposed immigration reform was deeply unpopular in McConnell’s home state of Kentucky, where he has said his Senate seat is targeted by Democrats.

If McConnell decides to back Reid over Corburn and DeMint, he’ll doom any effort to restore the original earmark reform language. What’s so sad is that McConnell would score huge points with the conservative base if he challenged Reid, especially in light of the earmark scandal engulfing Sen. Ted Stevens (R.-Alaska). The earmark language that was stripped from the bill was approved on a 98-0 vote in January.

It’s hard to understand why McConnell won’t come out against this bill. Perhaps DeMint has tested him one too many times? Yesterday, McConnell was quoted by the Associated Press blaming DeMint: “[W]e made it difficult on ourselves because one of our members prevented us from going to conference.” That member was DeMint. His reasoning made sense. Reid refused to guarantee that the earmark reform language would remain intact. Besides, Republicans would have been rolled over in the Democrat-led conference committee, giving them no leverage once the bill reached the floor.

A chance to reform the earmarking process won’t come along again anytime soon. It would be unfortunate if Republicans let this bill slide through in its current form.

UPDATE: I just got word from a trusted source that Reid’s office is spreading lies about the ethics bill. Here’s a Myth vs. Fact document about earmark reform that sets the record straight.