Supreme Court nominee Brett Kavanaugh declared fervently at his Senate confirmation hearing Tuesday the court "must never, never be viewed as a partisan institution." But that was at the end of a marathon day marked by rancorous exchanges between Democrats and Republicans, including dire Democratic fears that he would be President Donald Trump's advocate on the high court.

The week of hearings on Kavanaugh's nomination began with a sense of inevitability that the 53-year-old appellate judge eventually will be confirmed, perhaps in time for the first day of the new term, Oct. 1, and little more than a month before congressional elections.

However, the first of at least four days of hearings by the Senate Judiciary Committee began with partisan quarreling over the nomination and persistent protests from members of the audience, followed by their arrests.

Strong Democratic opposition to Trump's nominee reflects the political stakes for both parties in advance of the November elections, Robert Mueller's investigation of Trump's 2016 campaign and the potentially pivotal role Kavanaugh could play in moving the court to the right.

Democrats, including several senators poised for 2020 presidential bids, tried to block the proceedings in a dispute over Kavanaugh records withheld by the White House. Republicans in turn accused the Democrats of turning the hearing into a circus.

Trump jumped into the fray late in the day, saying on Twitter that Democrats were "looking to inflict pain and embarrassment" on Kavanaugh.

The president's comment followed the statements of Democratic senators who warned that Trump was, in the words of Sen. Richard Blumenthal of Connecticut, "selecting a justice on the Supreme Court who potentially will cast a decisive vote in his own case."

In Kavanaugh's own statement at the end of more than seven hours of arguing, the federal appeals judge spoke repeatedly about the importance of an independent judiciary and the need to keep the court above partisan politics, common refrains among Supreme Court nominees that had added salience in the fraught political atmosphere of the moment.