WASHINGTON - U.S. President Joe Biden met Thursday with Senate Democrats in a last-ditch plea to overhaul the country's election laws even as one fellow Democrat pointedly said she would not support changing the Senate's legislative rules to circumvent uniform Republican opposition to establishing national voting rules.

Biden met with most of the Senate Democratic caucus over lunch to voice his support for two measures that would greatly increase federal oversight over congressional and presidential elections and establish uniform voting rules across the country. The bills would erase more restrictive regulations adopted by Republican-controlled legislatures in at least 19 states.

As he left the lunch, however, Biden voiced little optimism about his chances of winning approval for the legislation, telling reporters, "I hope we can get this done. The honest-to-God answer is, I don't know that we can get this done.'

With all 50 Republicans in the 100-member Senate opposed to the two pieces of legislation Biden supports, Democrats can only approve them by changing the Senate's filibuster rule that forces proponents of any contentious legislation to amass a 60-vote supermajority. Democrats want to pass the legislation by a 51-50 simple majority vote with Vice President Kamala Harris casting the tiebreaker.

FILE - In this image from Senate Television, Sen. Kyrsten Sinema, D-Ariz., speaks on the floor of the U.S. Senate on Jan. 13, 2022.

But shortly before Biden arrived on Capitol Hill to meet with the Democratic senators, Senator Kyrsten Sinema of Arizona said in a Senate speech that she supports voting rights but would not vote to change the chamber's filibuster, even for voting rights.

Another centrist Democratic lawmaker, Senator Joe Manchin of West Virginia, has also consistently voiced his opposition to changing the filibuster rule.

Sinema said, "These bills help treat the symptoms of the disease, but they do not fully address the disease itself. And while I continue to support these bills, I will not support separate actions that worsen the underlying disease of division infecting our country" by changing the Senate's use of the filibuster that allows the minority party to block legislation it opposes.

Her view on the filibuster, while not new, was a blow to Biden's efforts to advance a major piece of his legislative agenda.

Change of view

The president, himself a senator for 36 years before serving as vice president and winning the presidency, had voiced reservations during his run for the White House about abandoning the Senate filibuster.

But on Tuesday in Atlanta, he said, "Today I'm making it clear. To protect our democracy, I support changing the Senate rules whichever way they need to be changed to prevent a minority of senators from blocking action on voting rights."

Democrats say the legislation is needed to curb voting rules adopted in Republican-led states that make it more difficult to vote, such as by curtailing mail-in voting and limiting the number of days allowed for early balloting ahead of the traditional election days in early November.

Former President Donald Trump has falsely claimed the more lenient voting rules employed in 2020 led to fraud that cost him reelection, although voting officials for a year have concluded that any irregularities that occurred would not have changed the outcome of the election.

Senate Minority Leader Mitch McConnell, R-Ky., speaks during a news conference on Capitol Hill in Washington, Dec. 7, 2021.

Republican Senate Minority Leader Mitch McConnell has adamantly opposed the Democrats' efforts to approve the voting changes and assailed Biden's speech in Atlanta. McConnell has said the changes would amount to a federal overreach for Democrats to control elections, "so that one political party can take over our nation's elections from the top down."

On Thursday, as the legislative maneuvering came to a head, McConnell said, "Nobody in this country is buying the fake hysteria that democracy will die unless Democrats get total control."

"There's a path forward for my Democratic colleagues to respond to the country they have so badly disappointed, but it isn't to try to break the Senate and rewrite election laws, it's to actually start tackling the issues that American families need tackled," he said.

Another Republican lawmaker, Senator John Thune of South Dakota, said after Sinema spoke, "She's just expressing a frustration that [her Democratic colleagues] don't appear to be listening to her. She's been clear. She's been public from the beginning about this, and they seem to continue to think that somehow they're going to switch her, and the more they do that, I think the more dug in she's gotten."