Throughout her more than two decades in the Senate, Sen. Susan Collins (R-Maine) has positioned herself as an independent Republican who vigorously favors a woman’s right to reproductive choice.

She cemented that reputation last year, when she cast a critical vote to stop the Trump administration from repealing the Affordable Care Act and stripping health care from thousands of her constituents.

And, for her entire career, Collins has appeared to be truly committed to a pro-abortion rights position.

Why, then, are there rumors that she is considering a vote to support the appointment of Brett Kavanaugh to a lifetime position on the Supreme Court when there is clear evidence that he would provide the deciding vote to overturn or severely curtail women’s rights to an abortion, take away access to health care for millions, and has written that presidents shouldn’t be held accountable for criminal acts while in office?

There are at least three potential reasons:

1. Perhaps she is more gullible than an experienced senator has the right to be.

Some have argued that Collins is buying Kavanaugh’s meaningless assurance that Roe vs. Wade is “settled law” and would be a balanced, mainstream jurist – ignoring the string of decisions and writings establishing clearly that he totally opposes a woman’s right to control her reproductive life.

Maybe, the argument goes, his smile and his “I’m just a wonderful father and Little League coach” veneer have blinded her to his consistent record as a judicial radical who, if given the chance, would very likely declare the Affordable Care Act ― and its protection of people with pre-existing conditions ― unconstitutional.

Maybe he didn’t really mean that presidents should not be held accountable for criminal acts while they are in office because it would create such a “distraction.”

No. She’s too smart for that.

2. Maybe Collins has decided not to run again and doesn’t want to spoil her chances for a highly lucrative job with some big GOP donor.

It wouldn’t be the first time a member of Congress sold his or her soul so they could cash in after leaving office. In 2003, when Medicare Part D was passed, then-Rep. Billy Tauzin, the GOP chair of the energy and commerce committee, insisted on a provision actually preventing Medicare from negotiating for the lowest prices with drug companies. The next year, he left Congress and was rewarded with a million-dollar-a-year job as head of PhRMA, the powerful pharmaceutical lobby.

Maybe that’s what Collins has in mind when her current Senate term ends in 2020.

The problem with that theory is that her history really suggests she likes to wake up in the morning, look herself in the mirror and see a decent person ― not the kind of senator who would sell out the interests of her constituents to make herself rich.

3. She and her aides have made a political calculation that a vote for Kavanaugh will help her re-election chances in 2020.

They may figure that she is likely to face a stiffer challenge from the right in her Republican primary than she would in the general election. Best not to give the GOP base another reason to move against her.

It is correct that Collins may face a right-wing primary challenge, but is it really more likely to succeed if she votes against Kavanaugh?

Many hard core Trump voters will never trust Collins again because she voted to save the ACA, supports abortion rights and periodically questions Trump. To them, her vote on Kavanaugh won’t make a dime’s worth of difference.

And recall, as the Intercept reported, “There is no grassroots energy rallying for Kavanaugh. None.” You don’t see rallies like the ones the tea party mobilized to fight the ACA. You only see an extraordinary national movement to stop Kavanaugh.

So, if that is Collins’ calculation, she is dead wrong.

In fact, a vote to confirm Kavanaugh would be political suicide. Such a vote will not simply make it harder for her to be re-elected. If Collins votes to put Kavanaugh on the Supreme Court, she will unleash the elements of a political storm that will sweep her out of office.

Collins ― and all Republicans in swing states ― already face stiff political headwinds in 2020.

A blue wave is building for the 2018 midterms. It is likely to do nothing but intensify in the buildup to 2020, when Trump himself will be on the ballot. Every day brings new outrages from the White House that are repugnant to swing voters ― and especially the women ― of states like Maine. This year, Democratic turnout is setting records. By 2020, Democratic mobilization efforts will be at a fever pitch.

A vote for Kavanaugh would destroy Collins’ independent, pro-health care, pro-women’s rights reputation.

Collins’ best defense against that 2020 Democratic gale is her political brand as a pro-health care, pro-abortion rights independent, who will defend her constituents at all costs.

That brand was clearly established by her heroic vote to save the Affordable Care Act and her consistent support of women’s rights.

And all of the political polling in Maine makes it clear that Mainers don’t want anyone to take away a woman’s right to choose ― or their health care. Nearly two-thirds of Maine residents support a woman’s right to choose. And the ACA has overwhelming support.

A PPP poll in late August found that if Collins votes to confirm Kavanaugh, “voters are far less likely to support her in her next election by 16 points ― with 47 percent saying they would be less likely to vote for her and 31 percent more likely.”

What’s more, by 22 percentage points (56 to 34) Maine voters don’t believe Collins should vote to confirm Kavanaugh until his full record is made public, including 57 percent of Mainers over 65, and 53 percent of independents.

Whether she likes it or not, Collins ― along with her political soulmate, Lisa Murkowski of Alaska ― are the two swing votes who will decide if Kavanaugh is placed on the Supreme Court. And, like it or not, Kavanaugh will be the swing vote on the Supreme Court.

Collins will be held personally responsible for every anti-choice, anti-health care, pro-Trump, anti-immigrant ruling the Supreme Court makes over the next two years. And she’ll even be held responsible for the anti-choice, anti-health care, pro-Trump votes Kavanaugh takes, even if he’s not in the majority of the court.

Is Collins really willing to risk her entire political legacy on Kavanaugh’s vague assurances that he will impartially judge all of the facts?

A vote for Kavanaugh would make Collins the poster child for betrayal.

The thing that will make a strong political wind into a perfect storm will be voters’ sense of betrayal.

Collins’ vote against repeal of the ACA, her vocal support of abortion rights, and her willingness to stand up to the far right of the Republican Party have made her a hero to many Maine voters ― and people around the country.

They have invested emotionally in her.

If Collins becomes one of the deciding votes for Kavanaugh, many of these voters will feel betrayed. Already, a group of Maine voters has begun recruiting pledges to support Collins’ 2020 opponent if she votes for Kavanaugh. To date, thousands of people have pledged almost $500,000 ― a sum that will explode if she votes to confirm Kavanaugh.

And, as we all know, hell hath no fury like a voter scorned.

Robert Creamer is a longtime political organizer and strategist, and author of the book: Stand Up Straight: How Progressives Can Win, available on Amazon.com. He is a partner in Democracy Partners. Follow him on Twitter @rbcreamer.