By Grace Sparks

(CNN) -- The party lines are set. Republicans want Brett Kavanaugh confirmed to the Supreme Court and Democratic leaders like Chuck Schumer are already mobilizing against Kavanaugh.

With ailing Sen. John McCain not voting, neither party can afford to lose a vote from their side. And that will put some senators in a tough position as Democrats move to make Kavanaugh's nomination specifically about abortion rights.

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"I believe if we can prove to the American people, which I believe is truly the case, that this nominee will lead to a court that repeals women's reproductive freedom, repeals ACA with its protections for pre-existing conditions, we will get a majority of the Senate to vote for it," Schumer said Tuesday on CBS.

Alabama Sen. Doug Jones is a Democrat representing a red state, which probably has something to do with his open mind to Trump's Supreme Court nominee.

Jones said Sunday, before the nominee was revealed as Brett Kavanaugh, that he could vote either way.

"I don't think my role is to rubber stamp for the President, but it's also not an automatic knee-jerk no, either," Jones told CNN's Dana Bash on "State of the Union," before Kavanaugh's nomination.

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While the majority in state Jones represents is likely to be very supportive of Kavanaugh, it's equally likely that those who voted Jones in to office in 2017 will be equally unsupportive.

Take the issue of abortion, which was a key issue in Jones' upset victory and it's gearing up as a key issue in Kavanaugh's impending nomination.

According to CNN's exit polling taken after the 2017 special election, more than half of Alabama voters in that special election (52%) said abortion should be illegal in all or most cases. But the 42% who said that abortion should be legal in all or most cases overwhelmingly voted for Doug Jones -- at 81%.

But there's no doubt that a senator like Jones faces more pressure to support the President than other Democrats, as he's located in a strongly red state.

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The opposite is true of Republican Sen. Susan Collins, of Maine, a supporter of abortion rights who represents a mostly blue state -- Maine is able to split its electoral college votes, with one district consistently blue and the second a battleground. Collins is considered a Republican who often works across the aisle and has voted with both Democrats and Republicans. She supported both Neil Gorsuch and President Obama's Supreme Court nominees. She's also said she won't support a nominee who is "hostile" toward Roe v. Wade.

How Kavanaugh answers questions about that case and the legal precedent it created will be key to his confirmation. During confirmation to a lower court, he promised to be deferential to the precedent. On the Supreme Court he could help change it.

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Republicans and independents voted for Collins in her 2014 election in large majorities of 97% and 69%, respectively. Even four-in-10 Democrats supported her.

But according to PRRI's American Values Atlas, in 2014, Maine had the 3rd highest support for legal abortion in the US -- with 67% who said it should be legal in most or all cases, following New Hampshire (73%) and Vermont (69%).

Sen. Bob Casey is the rare Democrat who opposes some abortion rights and who describes himself as "pro-life," but he opposed Trump's nomination for a reason unrelated to abortion and before he knew it was Kavanaugh. Casey stated on Monday that he wouldn't support the nominee for the Supreme Court, according to the Pennsylvania lawmaker's office. He tweeted that his opposition to the nomination is largely fueled by anger about Trump choosing from a list Casey says was formulated by "the hard Right, who are funded by corporate America."

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Casey is up for re-election in the fall midterms, with every poll done between him and Republican Lou Barletta showing Casey with an advantage.

In a Suffolk University poll of Pennsylvania, taken in June, 73% of those who plan to vote for Casey in his upcoming election said that they want their vote to change the direction that Trump is leading the nation. Sixteen percent said that their vote isn't relevant to Trump and his policies.

Jon Tester is another Democratic incumbent senator running in a red state. CNN has rated the race as lean Democrat. Montana was about equivalent to the rest of the US's abortion views when asked in 2014 with 54% of Montanans saying abortion should be legal in some or all cases compared to 55% of the US at large.

Republican Sen. Lisa Murkowski was re-elected in Alaska in 2016 with 45% of the vote for her third term in office. Murkowski is outwardly supportive of abortion rights and has voted to fund Planned Parenthood with Democrats in the past.

Alaska is more for legal abortion than the US as a whole, in the 2014 PRRI Atlas, with 56% of respondents saying they support legal abortions.

But Murkowski, unlike Collins, voted against both of Obama's nominees to the Court.

This story has been updated to correct the percentage of Alaskans who support legal abortion.

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