(CNN) A Democratic measure aimed at eliminating short-term health care plans that don't cover pre-existing conditions failed in the Senate on Wednesday in a tied vote of 50-50.

Maine Sen. Susan Collins was the sole Republican to vote for the measure, put forth by Democrats.

The resolution was aimed at rebuffing a Trump administration rule that allowed some plans not to require coverage of pre-existing conditions, the latest action from the minority party's push to focus on the issue of health care going into the midterms.

Democratic Sen. Tammy Baldwin of Wisconsin used the Congressional Review Act to force a vote to overturn the Trump administration rule to expand short-term insurance plans . Forty-nine Democratic senators supported the resolution and they would have needed an additional Republican vote -- besides Collins -- to reach the 51-vote threshold for the measure to pass, though the GOP-controlled House would likely not have acted on the legislation. That made the series of events Wednesday morning a largely symbolic vote aimed at forcing moderate Republicans to possibly take a politically difficult vote on the record.

Short-term health plans don't have to adhere to the Affordable Care Act's regulations that protect people with pre-existing conditions. These plans can deny coverage or charge higher premiums to Americans based on their medical histories. And they don't have to provide comprehensive coverage.

The Trump administration made it easier to buy these plans — allowing people to buy coverage for just under a year, versus the 90-day limit imposed by the Obama administration.

"The Trump administration is rewriting the rules on guaranteed health care protections that millions of Americans depend on," said Baldwin, who's up for re-election this year in a state President Donald Trump won in 2016, in a statement before the vote. "These junk insurance plans can deny coverage to people with pre-existing conditions and don't have to provide essential health services like prescription drugs, emergency room visits and maternity care."

Baldwin also touted in her statement that more than 20 health organizations, like the American Heart Association and Planned Parenthood Federation of America, supported her effort.

Collins cited the lack of protections for those with pre-existing conditions in a statement explaining her vote.

"Short-Term Limited Duration plans do not provide protections for enrollees who suffer from pre-existing conditions," Collins said. "As I have often emphasized, it is essential that individuals who suffer from pre-existing conditions are covered. At the same time, we cannot ignore the fact that many individuals lack an affordable health insurance option. The underlying flaw in the Affordable Care Act is that it does not provide affordable coverage. But I believe this flaw can be addressed without jeopardizing protections for individuals with preexisting conditions."

The Congressional Review Act is a law that Republicans have used extensively since Trump came into office to overturn Obama-era regulations.

Sen. Lisa Murkowski, an Alaska Republican who voted against her party to protect the Affordable Care Act in 2017 , told CNN that she would not be supporting Baldwin's resolution.

GOP leaders blasted the Democratic proposal in advance of the vote, saying it would take away a low-cost insurance option for families who Republicans argue were hurt by the Affordable Care Act, more commonly referred to as Obamacare.

"Surely, they must have a better answer than snatching away one of the remaining options that some Americans still prefer to anything Democrats have been able to come up," Senate Majority Leader Mitch McConnell said before the vote. "Our constituents deserve more options, not fewer."

"I think the most important thing to remember is that Obamacare is not the only way to get pre-existing condition coverage. There are better ways to do it," said Senate Majority Whip John Cornyn said in advance of the vote. "That is what they would like to get people to buy into, and it's just fundamentally not true."

But Democrats, still stinging from the bitter fight over the confirmation of now Supreme Court Justice Brett Kavanaugh , are emphasizing this new rallying cry during the final four week push to the midterms, with one senior Democratic aide telling CNN, "The vote this week puts Republicans on record, and is just the start of our relentless focus on health care down the stretch."

In remarks on the Senate floor on Tuesday, Senate Minority Leader Chuck Schumer called the Trump administration's rule on short-term health care plans "fundamentally misguided policy."

"All of my colleagues should vote for this, but I suspect my colleagues on the other side of the aisle have a different idea because ever since taking control of congress and the presidency, Republicans have deliberately, relentlessly undermined Americans' health care," he said.