Updated at 4:50 p.m. to include five more senators who said they'd vote against Whitley, bringing the total of Senate Democrats opposed to him to eight.

AUSTIN — The pressure continued to mount on embattled interim Secretary of State David Whitley on Thursday, as more than 30 civil rights and community groups called for his ouster and a majority of Senate Democrats publicly stated their opposition to his nomination.

Sen. José Rodríguez of El Paso, who leads the Senate Democratic Caucus, released a statement saying the "damage has been done" in Whitley's botched rollout of an investigation that questioned the citizenship of tens of thousands of Texas voters.

"I firmly believe in the governor's prerogative to make appointments; only in extreme circumstances would I not defer to the governor's choices. In this case, however, the damage has been done," he said. "Many Texans mistakenly believe evidence of voter fraud has been found. Many now fear to vote, even though they are eligible. Although it is a difficult decision, I cannot support Mr. Whitley's nomination to serve as secretary of state."

Sens. Nathan Johnson of Dallas, Beverly Powell of Burleson and Borris Miles of Houston also said Thursday that they would not support Whitley's nomination. Sen. Judith Zaffirini of Laredo said she did not intend to vote for him at this time.

Those Democrats joined Sens. Royce West of Dallas, Kirk Watson of Austin and José Menéndez of San Antonio in publicly stating their opposition to Whitley, whose confirmation is nearing a crisis point because he needs the support of at least two of the remaining four Democrats if he wants to secure his job full-time.

In a troubling sign for Whitley, the Republican-dominated nominations committee left the vote pending for a third time Thursday. Flower Mound Sen. Jane Nelson, a Republican, told The Dallas Morning News this week that she didn't know if the Senate was going to confirm Whitley.

"I think we would have voted on him if he was going to be," she said. "But I haven't counted votes."

But Whitley, whom Gov. Greg Abbott appointed in December, continues to have his full support, a spokesman for the governor said last week.

Early Thursday morning, 35 civil rights and community groups sent letters to Senate Democrats urging them to block Whitley's confirmation.

“Under no circumstances should Mr. Whitley be allowed to continue to serve as the Texas secretary of state. The Senate Democratic caucus — and each of you individually — have the power to unite in defense of the voting rights of all Texans and stop his confirmation,” the groups wrote in a letter sent to Democratic senators Thursday morning. “We call on you to affirmatively block the confirmation of David Whitley for Texas secretary of state.”

A spokesman for Whitley said he is in the Rio Grande Valley visiting with public officials and community leaders, including local election officials and education leaders, with whom he is committed to working to ensure that all eligible Texans can make their voices heard at the ballot box.

"Secretary Whitley deeply respects the Senate's role in the nominations process and will continue to seek an open line of communication with senators to address any questions or concerns," said Sam Taylor, a spokesman for the office.

The backlash against Whitley stems from a January advisory his office sent to counties. It said the state had identified 95,000 people on Texas voter rolls who received driver's licenses while legally in the country, but not U.S. citizens. The advisory said 58,000 of those had voted in one or more elections since 1996 and asked counties to investigate whether noncitizens were voting in Texas elections.

But civil rights groups and voting rights advocates said those numbers were flawed and did not account for people who had received their licenses while not citizens and then became citizens. The state admitted in court Wednesday that 20,000 people who had already proved their citizenship to the Department of Public Safety had been erroneously placed on the list.

Three different groups have sued the state to stop the investigations, which the plaintiffs allege infringe on the voting rights of naturalized citizens in the state, particularly Latinos, who have a higher rate of naturalization than other groups.

“It has become exceedingly clear that Mr. Whitley is unfit to serve in that office,” the letter reads. “Mr. Whitley has targeted naturalized citizens for disenfranchisement and falsely accused them of committing voter fraud.”

The letter’s signatories, which include the League of Women Voters of Texas, the Texas NAACP, the League of United Latin American Citizens and the Texas Democratic Party, took Whitley to task for being unable to answer questions during his confirmation hearing in front of the Senate Nominations Committee about how his office handled the advisory’s rollout.

“Mr. Whitley demonstrated an embarrassing lack of knowledge about the process he initiated,” the letter reads.

Several of the groups that signed the letter, like the Texas Civil Rights Project and Common Cause, opposed for the first time in their history the appointment of a secretary of state.

Mimi Marziani, the president of the Texas Civil Rights Project, said the position required someone who was competent, evenhanded and was paying attention to details.

"Very unfortunately, David Whitley has already proved that he is none of those things and for those reasons he should not be confirmed," she said.

Calling Whitley’s conduct “disqualifying,” the groups said he “knew or had reason to know that a substantial number of these 58,000 Texas residents had not voted unlawfully, and still he sent the entire list to the attorney general for criminal investigation and potential prosecution.”

“Mr. Whitley’s actions demonstrate a level of incompetence that we cannot accept in a position tasked to protect and advance our most fundamental rights of civic participation,” the groups wrote.

Abbott appointed Whitley in December after previous secretary of state Rolando Pablos resigned. But he still needs to be confirmed by the Senate. That would require 21 votes, and with only 19 Republicans in the chamber, who will likely back the Republican governor's nomination, Whitley’s fate is in the hands of Democrats, whose constituents are clamoring for them to reject him.

"Democrats in the Texas Senate have a clear choice: Stand up to voter suppression or be complicit in Governor Abbott's divisive agenda," said Jose Garza, executive director of Workers Defense Action Fund, one of the groups that signed the letter. "Our powerful movement of Texans rejects attacks on immigrant families, working families and our democracy — like the one staged by David Whitley. It's time for Senate Democrats to pick a side."

Manny Garcia, executive director of the Texas Democrats, said he was confident that Senate Democrats "would do the right thing."

"Every day that David Whitley sits in the secretary of state's office is a threat to our democracy," he said. "Texas Senators should vote no."

Austin correspondent Lauren McGaughy contributed to this report.