Hillary Clinton closed a three-day campaign fundraising swing through Texas and New Mexico on Thursday with a rare public appearance at Texas Southern University in Houston and a stemwinder on voting rights.

She took no questions and spoke with no reporters, but angrily complained that Texas voters can present their concealed-carry gun permits as a voter ID, but not their college student identification cards.

Clinton was received with wild applause at the historically black college, but organizers arranged the 8,100-seat basketball arena so that three-quarters of the seats were roped off and empty.

They added rows of chairs on the floor, but 15-foot-tall blue curtains draped all around blocked the view of entire sections of empty seats, leaving the impression that Clinton couldn't fill the room.

The university didn't provide a crowd count, but an arena security official estimated that there were 2,200 in attendance.

Scroll down for video

CAN YOU HEAR ME NOW? Clinton grabbed both microphones on her lectern and railed against Republicans who she said want to freeze minorities and young voters out of the election process

SMALL STAGE: This photograph shows the setup for Hillary Clinton's June 4, 2015 speech at Texas Southern University. Rows of balcony seats (at bottom) were available, and more chairs were lined up on the basketball floor (center), three quarters of the arena seating was placed off-limits behind giant blue curtains

Clinton spoke for 31 minutes with the aid of a teleprompter, alleging that 'hundreds of thousands of registered voters in Texas' are being disenfranchised by a conspiracy of conservatives who want to freeze out Democratic-leaning voters.

And elsewhere, she said, in the Carolinas, election officials have changed the location and open hours of polling places in order to flummox poor and minority voters.

Clinton also complained that state and local officials in southern states have crusaded against early voting plans, same-day voter registration, and pre-registration systems that target 16- and 17-year-olds in high schools.

Changes to voting laws in the South came fast and furious after a 2013 Supreme Court decision that revoked key provisions in the Voting Rights Act.

That law's 'special protections,' as Clinton put it, had forced southern states with histories of discrimination to get permission from the federal government before putting new election laws in place.

Texas moved to amend its voting laws just hours after the decision to end that system was handed down.

AWARDED: Clinton received the inaugural Barbara Jordan Gold Medallion for Public-Private Leadership

Barbara Jordan, the late Texas member of the US House of Representatives, was the first African-American female elected to Congress from a state in America's deep south. SHe is shown here making a landmark keynote speech to the Democratic National Convention in 1976

Texas Southern, a historically black university, honored Clinton with a public service award named for the late Rep. Barbara Jordan, the first black female member of Congress from the Deep South.

'She was a staunch advocate for the Voting Rights Act, which had helped make it possible for her to be elected,' Clinton said Thursday, lamenting that the federal law's 'heart has been ripped out' by America's most senior jurists.

In the wake of that decision, Clinton said Thursday, Americans have seen a torrent of 'new laws that make it harder than ever to vote.'

She warned against 'a sweeping effort to disempower and disenfranchise people of color, and young people and poor people from one end of this country to the other.'

Minority communities' feelings of being especially challenged on Election Day, she said, 'just didn't happen by accident. And it is just wrong.'

Americans support voter ID laws, the measures Clinton railed hardest against, by large margins.

In deep-red Texas, according to a University of Texas poll in late 2014, support runs at 3-to-1.

Her exploitation of this issue only underscores why voters find her dishonest and untrustworthy. Republican National Committee spokesman Orlando Watson, on HIllary Clinton's June 4, 2015 speech

But voter laws will be a political issue in 2016 that Democrats seem happy to embrace, despite the odds stacked against them.

In nearly every state that has measured the phenomenon, black voter participation rates went up, not down, after measures Republicans favor were put into place.

Moments later she invoked the names of Wisconsin Gov. Scott Walker and Texas Gov. Rick Perry as legal abusers, drawing hisses from the audience.

Perry announced the launch of his presidential campaign hours before Clinton spoke. Walker has yet to formally enter the 2016 race.

Clinton's top campaign lawyer, Marc Elias, has filed lawsuits challenging Walker's election laws.

The former first lady said the next presidential contest will help determine whether blacks, Hispanics, millennials and women are marginalized in the voting process.

She advocated leapfrogging the states' laws, with Washington, D.C. forcing them to implement universal, automatic voter registration for all citizens.

'Every young man or young woman should be automatically registered to vote when they turn 18 unless they actively choose to opt out.'

America, like most nations, uses an 'opt-in' system instead, requiring citizens to take the step of registering before they become eligible.

Republicans have complained that unilaterally broadening the voter rolls will open up new avenues to abuse the system.

Clinton scoffed at the idea, mocking what she said was a 'phantom epidemic of election fraud.'

Catherine Engelbrecht, the founder of the conservative group True the Vote, said Thursday afternoon that putting the federal government in charge of a sweeping expansion of voting rules would introduce the possibility that illegal immigrants could cast ballots.

PEST CONTROL: Clinton's people, and Texas Southern University, kept reporters at bay on Thursday with steel barricades in the arena

'For such a federal policy to work, Washington voter registrars would be dependent on Social Security, driver license and other social service agencies already proven to commingle citizens and illegal aliens for new records,' she said.

Orlando Watson, the Republican National Committee's communications director for black media, fired a broadside at her following the speech.

' Hillary Clinton’s rhetoric is misleading and divisive,' Watson said. 'In reality, the vast majority of Americans – including minority voters – support commonsense measures to prevent voter fraud.'

'Clinton’s shameless attacks ignore the fact her Democrat-led home state of New York does not allow early voting while dozens of Republican-led states do. Her exploitation of this issue only underscores why voters find her dishonest and untrustworthy.'

But Clinton played to her crowd, saying convicted felons who have completed their sentences should have their voting rights restored.

That brought a round of applause from the largely black audience at Texas Southern.

She called also for Internet voter registration, a system that would keep no one in a voting line for more than 30 minutes, and demanded a national system that would leave polls open for at least 20 days prior to the actual Election Day.

'If families coming out of church on Sunday feel inspired to go vote, they should be free to do just that,' she said.

Reporters covering Thursday's event were warned by university staff to remain behind a security barrier erected on the floor of the arena.

'There will NO opportunities to interview Hillary Clinton,' an email advisory to journalists read. 'Her speech will be her interview.'

Clinton will finish her Texas fundraising trip with a private event at 6:30 p.m. Thursday in Houston, capping off a two-day swing featuring four such high-dollar collection efforts.