Washington (CNN)Republican Sen. Mitt Romney on Sunday defended the filibuster and blasted Democrats calling for its elimination, dismissing their latest discussion to end it in order to pass voting rights legislation as "an unserious partisan effort aimed at messaging and energizing that party's base."

       "The need to marshal 60 votes to end a filibuster requires compromise and middle ground. It not only empowers the minority but also has helped to keep us centered, fostering the stability and predictability essential to investment in people, in capital and in the future," Romney, a moderate Republican who represents Utah, wrote in an op-ed published in The Washington Post, adding that nixing the filibuster "would fundamentally change the distinct and defining role of the U.S. Senate."

       The comments from Romney come as renewed attention is being paid to the Senate rule as Democrats look for ways to quickly pass some key legislative items, such as a voting rights bill. Though two key moderate Democrats have expressed opposition to altering the filibuster, President Joe Biden said earlier this month that he was open to doing so in order to pass voting rights legislation, reneging on his previous support for preserving the rule.

       Related interactive: Congress is at the mercy of one Senate rule, the filibuster

       "The Democrats' latest justification for eliminating the filibuster is Republicans' unwillingness to pass partisan election-reform legislation. Democrats have filed these bills numerous times over numerous years, almost always without seeking Republican involvement in drafting them," Romney wrote.

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       "Anytime legislation is crafted and sponsored exclusively by one party, it is obviously an unserious partisan effort aimed at messaging and energizing that party's base. Any serious legislative effort is negotiated and sponsored by both parties."

       All Democrats would have to be on board with making such a change, as Democrats have the slimmest of majorities in the Senate.

       Romney chastised Democrats for flip-flopping on the issue and rejected the claim that the filibuster is racist, specifically targeting former President Barack Obama's use of this argument after he previously defended the filibuster. The senator and 2012 Republican presidential nominee wrote that Obama's apparent reversal "is both jarring and deeply disappointing."

       Romney also suggested that a change to the filibuster rules could backfire on Democrats, saying that it could be used against them if Republicans retake control of Congress next year and former President Donald Trump runs for reelection in 2024 and wins.

       "Have Democrats thought through what it would mean for them for Trump to be entirely unrestrained, with the Democratic minority having no power whatsoever? If Democrats eliminate the filibuster now, they -- and the country -- may soon regret it very much," he wrote.