Sen. Claire McCaskill (D-Mo.) on Monday predicted her Democratic colleagues would ultimately keep Sen. Ben Nelson's (D-Neb.) forthcoming abortion amendment out of the chamber's healthcare bill.

In an interview with CBS's "The Early Show," the Missouri senator signaled her dissatisfaction with that proposal, which Nelson plans to introduce today, and repeated her wish to preserve the healthcare bill's current abortion language.

"Well, let's be clear, the bill as it stands does continue current law, which says no federal money can be used to fund abortions," McCaskill said. "What this amendment does is goes further, it actually says you can't use private money in a private market for any kind of health services related to abortions. And frankly, I think that goes too far."

Nelson's abortion amendment could prove political troublesome for Democrats. While many in the party dislike his proposal, McCaskill included, it remains unclear how Nelson might ultimately side on a healthcare bill that does not contain it. The Nebraska senator has previously signaled he could only support his chamber's proposal if it contains tough abortion language, and Democrats need his vote in order to secure against an expected Republican filibuster.

"I think we're getting there," McCaskill said about negotiations within her own party, on matters of abortion and the public plan -- another contested component of the bill. "Failure is not an option."

At the very least, Nelson's amendment is likely to score a handful of Republican votes -- even though those GOP lawmakers are poised to vote against Democrats' motion to end debate.

One of the bill's chief opponents, Sen. Lamar Alexander (R-Tenn.), stressed alongside McCaskill this morning that the bill still contained serious flaws. He also dismissed the suggestion Republicans were trying to stall debate, noting instead his party has tried repeatedly to engage the president on healthcare reform.

"That's really an amazing statement," Alexander said of the argument the GOP was delaying reform. "The president was elected on the idea of open meetings," he added, noting the president stopped by Capitol Hill on Sunday to meet only with Democrats, not Republicans.

"The biggest problem is that the Democrats are using Medicare as a piggy bank to pay for a big new government program," Alexander said.