These are difficult moments for Democrats across the state as they ponder what to do in the U.S. Senate race.

Party activists worry that another weak showing in a major race will diminish the party. Progressives want one of their own in the Senate. Many women would like to see Sen. Olympia Snowe replaced by another woman.

Hanging over it all is the memory of 2010, when enough Democrats stuck with Libby Mitchell, long after it was clear she couldn’t win, to hand the race to Paul LePage.

While the dynamics of this race are different, with Angus King, a popular former governor who has led the race from the beginning: and Dill, a Democratic nominee without Mitchell’s long record of service and stature.

At this point in the 2010 race, Mitchell had a plausible road to victory, but the question for Democrats is the same.

For months King seemed so far ahead that Democrats could cast their vote for Dill and not materially affect the outcome. All that changed last week as polls showed the race tightening and raised the prospect of a Summers victory.

While some Democrats fret over who King will caucus with, there’s no such confusion with Summers. Despite being a lifelong moderate, Summers is now entirely in the control of the far right money guys in Washington. On position after position he seems to robotically read from their playbook.

A Summers victory could hand the Senate to Republicans and would most definitely reflect the end of an era in which we’ve sent moderate senators to Maine who’ve subsequently gained national stature. So it’s reality check time for Democrats.

Let’s start with the overall game plan of the Republican Super-PACs in Washington, with an excerpt from a recent U.S. Chamber of Commerce newsletter. ‘A win for Republicans depends in part on driving up Dill’s numbers. If she pulls enough voters away from King, then Summers can coast to a win without a majority of the vote. Several outside Republican groups have come in touting Dill as a liberal to help boost her numbers, and it appears to be working’.

These Super-PACs know a few things that Democrats should carefully consider.

• Dill can’t win. If you had a bank of super-computers whirring for a week you couldn’t produce a mathematical scenario in which she might win this race. What you would produce are various scenarios in which Dill gets just enough votes to hand the race to Summers and gives Republicans control of the U.S. Senate.

• It’s all about the numbers. In a three-way race the math is pretty simple. If one candidate gets 40 percent of the vote and another gets 21 percent the third one can only get 39 percent and the race is over. The Republicans want to get Summers to 40 percent and to push enough support from King to Dill to get her to 21 percent. That would make Dill the ‘spoiler’ in the race and give Summers his best chance of winning. That’s exactly why the Super-Pacs are funding Summers positive ads, King attack ads and glowing ads for Dill.

• Republicans control Dill’s destiny. Dill now holds the distinction of being the first major party candidate for statewide office whose television campaign is being paid for and run by her opposition. Were it not for the $400,000 dollars that Republican Super-PACs have spent trying to trick Democrats into supporting her, she’d still be mired in single digits in the polls.

If the Senate race continues to tighten over the next few weeks there isn’t anywhere for Dill to go. As the 25-30 percent of Democrats who now support her realize that she can’t win they’ll begin to shift to King. If the PAC ads allow her to rise in the polls beyond 21 percent and to threaten Summer’s position, Republicans will quickly replace their chirpy Dill ads with forcefully derisive attacks.

I don’t recount any of this with any joy. Dill seems to be a good person who’s devoted a lot of time to making her community and state a better place. But that isn’t enough reason to risk having a Sen. Summers representing Maine.

While Democrats don’t have the power to elect Dill, they do have the power to decide whether the next senator from Maine will be King or Summers. But to exercise that power, Democrats need to stand up now.

In 2010, too many Democrats dallied and the party paid the price.

If Democrats repeat that error, Maine may well have another far right voice representing us to the nation.

But this time the name on the door won’t be Paul LePage, it will be Charlie Summers.

Alan Caron is a lifelong Mainer, a disgruntled independent Democrat, an author of “Reinventing Maine Government” who served on Paul LePage’s transition team and a supporter of Angus King. He is also President of Envision Maine, a non-partisan organization working to promote Maine’s next economy. He can be reached at:

alancaroninmaine@gmail.com.