ORANGE CITY, Iowa — Senate Judiciary Committee Chairman Charles E. Grassley (R-Iowa) said Tuesday that the deadlock at the Supreme Court over a high-profile case involving public employee unions has not changed his decision to block Merrick Garland’s nomination.

The court announced Tuesday morning that the justices split 4-to-4 on the question of whether forcing teachers to pay dues to the state’s teachers union violates their free speech rights. It is the most important case in which the court has been deadlocked since the death last month of Justice Antonin Scalia.

Public employee unions, which most often align with Democrats, heralded the split as a victory in a case conservatives had hoped to win.

But although Grassley said Scalia would probably have ruled against mandatory union dues, he argued that rushing to replace him would not have changed the outcome because any new justice would have had no say in cases that have already been argued.

“You have a situation where even if Scalia had died and we decided to move ahead with Garland, he wouldn’t have been involved, and you would have had the same decision,” Grassley said.

Congressional Democrats and the White House have highlighted the possibility of split decisions in important cases as a reason for Senate Republicans to hold a vote on Garland’s nomination to fill the vacancy at the court so that key constitutional questions are not left unanswered.

But Grassley, like other Republicans, have brushed off this concern even if in some cases a deadlocked court might let stand lower-court rulings that conservatives oppose.

Grassley said Tuesday that he has to be “consistent” with his pledge to not hold hearings on Garland in order to allow the next president to choose a nominee to fill Scalia’s seat. He also ruled out the possibility of holding hearings during a post-election “lame duck” session, even if that means allowing the next president to nominate a more ideological candidate than Garland, who is seen as a moderate.

“I have to be consistent,” Grassley said. “You can’t argue with the decision of the electorate.”

Grassley said that it would have been good to have a ninth justice to weigh in on the union case, but he expects the court will be able to resolve many cases going forward. He noted that Justice Elena Kagan has recused herself from several cases since joining the court in 2010 because of her previous role as solicitor general in the Obama administration, which has required eight judges to reach a decision.

“I think it proves that the court is going to be able to operate,” Grassley said.

Grassley has for weeks been asked to defend his decision not to hold hearings, including at three separate town hall meetings held in Iowa this week. The home-state response has been a mix of polite frustration from Democrats and activists who want to see Garland confirmed, applause from conservatives who worry an Obama nominee would drag the court to the left and confusion from some moderates who don’t see the harm in giving a qualified judge a chance to defend his record.

Democrats in Washington have called on Grassley to hold hearings in late April so that Garland could receive a vote in the full Senate in May. Republicans have been unwilling to consider that request, but Grassley said he expects that some Democrats may try to use Senate rules to force a vote on whether to consider the nomination.

Grassley said Democrats could try to force a vote through a rarely used tool called a discharge petition that would force the Judiciary Committee to send the Garland nomination directly to the full Senate for a vote.