Republicans may have thought that the issue of Judge Merrick B. Garland’s nomination to the Supreme Court had faded away like a summer hydrangea over the congressional recess. Democrats, however, are making sure that President Obama’s pick stays in the news.

On Thursday, Vice President Joseph R. Biden Jr. will be on Capitol Hill to join congressional Democrats at a news conference where they will push for a vote on Judge Garland, who was put forward by Mr. Obama in March and is now the longest pending Supreme Court nominee in American history.

Judge Garland will also have a meeting with Senator Patrick J. Leahy, Democrat of Vermont.

Senate Republicans, led by Mitch McConnell of Kentucky, have repeatedly said that they will not consider Judge Garland’s nomination to replace Justice Antonin Scalia, who died in February, this year. They say the power to appoint the justice’s successor should be left to the next president.

Mr. McConnell’s position on the matter could be severely undermined should Hillary Clinton prevail in the race for the White House this November.