Hillary Clinton on Monday urged a small crowd at UW-Madison to consider future rulings by the U.S. Supreme Court when casting a ballot in Tuesday’s presidential primary and in November’s general election.

Clinton, the former secretary of state and current front-runner in the race to become the Democratic presidential nominee, said to a group of invited guests at the Gordon Dining and Event Center that the next president is likely to appoint more than one justice to the nation’s highest court and warned of the impact of a Republican candidate making those choices.

“This election has ripped away the curtain and made it absolutely clear to everyone how essential the Supreme Court is,” Clinton said. “I will keep talking about it and advocating and calling on the Senate to do its job and I hope there will be a great chorus of voices across our land that will do the same.

“It’s our Constitution, it’s our court and it’s our future,” said Clinton, who stopped Monday in Madison and Milwaukee, kicking off a two-day tour of Wisconsin in advance of its April 5 primary.

The state provides Clinton an opportunity to all but seal her case that she should be her party’s nominee. If she wins here, Clinton then could sharpen her focus on her three potential Republican foes in the general election: businessman Donald Trump, U.S. Sen. Ted Cruz of Texas or Ohio Gov. John Kasich. Primary opponent Vermont Sen. Bernie Sanders is crisscrossing the state this week, too, and spoke to a crowd of thousands on Saturday in Madison.

Speaking to the invitation-only crowd of about 250, Clinton urged the Republican-led U.S. Senate to stop its blockade of President Barack Obama’s pick to fill the current vacancy on the high court, federal judge Merrick Garland.

Clinton said Republicans in the Senate who are refusing to hold confirmation hearings on Obama’s nominee are effectively ignoring the voice of voters who twice elected Obama.

“We chose a president — we chose him twice. And now Republicans in the Senate are acting like our votes didn’t count and President Obama is not still our nation’s leader,” she said.

Clinton also singled out Wisconsin’s own Sen. Ron Johnson, one of the Republicans who has declined to hold hearings or votes on Garland’s nomination. Johnson, R-Oshkosh, has called for Obama’s successor to name a justice, citing the “highly politicized atmosphere” of a presidential campaign.

It marked the first time Clinton has spoken so pointedly on the Supreme Court vacancy, created by the recent death of former Justice Antonin Scalia.

“This is their job but they refuse to do it,” said Clinton.

Betsy Ankney, campaign manager for Johnson, said Clinton’s comments were “ironic.”

“It’s ironic that career politicians like Hillary Clinton and (opponent former Sen. Russ Feingold) are saying ‘do your job’ given that it’s their decades in Washington that have led to out-of-control spending, dangerously weak national security, and big government infringement on our freedoms,” Ankney said in a statement. “Ron is doing his job by protecting the Second Amendment rights of Wisconsinites and working to find other areas of bipartisan agreement. Maybe these career politicians should follow the example of someone with real-world experience.”

Clinton closed the address by taking questions from the audience for about 30 minutes. When asked whether Garland fits her criteria for a Supreme Court justice, Clinton skirted the question and said she didn’t want to second-guess Obama’s pick.

But she offered that she would not appoint someone who thought Roe v. Wade, which legalized abortion nationwide, wasn’t settled law, or someone who was not troubled by the 2010 Citizens United v. FEC case that cleared the way for corporations, unions and nonprofits to raise unlimited funds to make independent expenditures on elections.

Clinton said during her address that if the high court did not overturn that decision, she would seek a constitutional amendment to limit the amount of money special interest groups may spend in elections.

“The idea, I believe, that money is speech turns our Constitution upside down,” she said.

Sanders is popular in Madison, especially among college students at UW-Madison. Even so, one of the first audience members to find their seats on Monday was Jack Nortman, a 21-year-old junior majoring in political science and history.

Nortman said Clinton represented to him a way to continue what he described as economic progress under Obama.

“I think for me it’s an issue of, are we going to move forward?” said Nortman.

Former Gov. Jim Doyle, who also attended the event, said he expects Clinton and Sanders to battle in a close primary but speculated Clinton would come out ahead.

“I think this is going to be a very, very close primary, which is a very different thing,” Doyle said. “I think Hillary will win Wisconsin in November, which is what counts.”

Wisconsin — as the 33rd state to vote in the Democratic presidential primary and 34th for the GOP — is shaping up as a pivotal contest for both parties.

For many Democrats, it is regarded as a state that Sanders must win to preserve a viable path to the party’s nomination.

Sanders, who held one of his first campaign events in Madison last summer, drew about 8,000 to the Alliant Energy Center on Saturday for a rally.

Polls show Clinton and Sanders locked in a tight race in Wisconsin.

A recent Marquette Law School poll showed Sanders leading by 1 percentage point.

Another poll by Emerson College pegged Clinton with a 6-point lead, 50 percent to 44 percent. Both leads fell within the polls’ margins of error.

Before Clinton left Madison, she stopped in Anthology on State Street with Madison Ald. Mike Verveer — buying about $110 worth of goods including a red, chunky necklace, a couple pins and a print of a Neil deGrasse Tyson quote: “The good thing about science is that it’s true whether or not you believe in it.”

Verveer said his parents are family friends of the Clintons. Verveer’s mother, Melanne Verveer, worked for Clinton when she was first lady.

Shop employee Lindsay Quella, 23, said she had about an hour notice before Clinton’s visit.

“There’s never been this many people in here,” she said, referring to journalists and campaign staff.

State Journal reporter Mark Sommerhauser contributed to this report.