Progressive stalwart Sherrod Brown of OH said: "I will make a decision after meeting with him". "This nominee will repeal Roe and women's reproductive freedom, will repeal ACA - far against what the American people want. They were going to war over it, and it all just continues to destroy their credibility", Gohmert told Fox News.
But fierce Democratic opposition alone will not be enough to derail Kavanaugh's confirmation.
The leading Republican to replace Sen. Susan Collins (Maine) and Lisa Murkowski (Alaska), seizing on their past support for abortion rights and their votes previous year to reject a bill that would repeal key parts of the ACA.
Justin Walker, a law professor at Louisville University and a former clerk for both Kavanaugh and Kennedy, wrote that the dissent was ultimately more an argument against the mandate than in favor.
Collins praised Kavanaugh's "impressive credentials and extensive experience" but promised a "careful, thorough vetting", while Murkowski pledged to conduct a "rigorous and exacting" review.
One of the biggest issues on which Kavanaugh is expected to have a say is the future of the Affordable Care Act, or Obamacare.
Amar's endorsement is remarkable because by his own admission, he strongly supported Hillary Clinton for president as well as President Obama's nominee for the Supreme Court, Judge Merrick Garland, whose confirmation was stalled by Republicans.
The Environmental Defense Fund (EDF) has yet to make a public statement regarding its stance on Kavanaugh's nomination. "If we can make that case, we will get a majority".
Kavanaugh also wrote that the Constitution already provides a check on executive power, because an impeached president is then subject to criminal prosecution. Cashman was a member of Georgetown Prep's Class of 1985 - a class that also included Trump's first Supreme Court pick, Justice Neil Gorsuch. "I do not apply an ideological test to their personal views".
The vice president said Kavanaugh's qualifications would be the key to his success. The others are Republican targets for the confirmation vote who come from Trump-won states where they face re-election this fall.
Many Democrats have latched onto Kavanaugh's statement about investigations into presidents.
A senior White House official says Trump called Kavanaugh on Sunday evening to inform him that he was his choice to be nominated to the Supreme Court.
Several in that group - which include Sens. Kamala Harris (D-Calif.), a top contender for her party's 2020 presidential nomination. And control of the Senate is in play, which wouldn't stop Trump from making another SCOTUS nomination if a liberal justice retires under his watch, but Democrats could try to mitigate that next pick's conservative lean. Like Trump's first nominee past year, Justice Neil Gorsuch, Kavanaugh would be a young addition who could help remake the court for decades to come with rulings that could restrict abortion, expand gun rights and roll back key parts of Obamacare.
While conservatives debated the semantics of Kavanaugh's decision, Democrats and liberal activists were overwhelmingly alarmed by the nomination.
The Judicial Crisis Network, which pushes for conservative judicial nominees, will launch a $1.4 million ad campaign aimed at Donnelly, Heitkamp and Manchin, according to a representative for the group.
Republican Sen. John Kennedy of Louisiana said he was bracing for a tough confirmation battle as Democrats focus on abortion.
"The bottom line, [Kavanaugh] will be a justice who will understand the employer's perspective, and I don't think it will be a significant change from Justice Kennedy in that regard", said Steven Suflas, a management-side attorney at Ballard Spahr law firm who argued a case before Kavanaugh.