Filibustering is a way more common practice by democrats than republicans. They used the technique 589 times in just the last six years. But now that republicans can take advantage of it, democrats want to curb or eliminate the legislate tactic that has been around since the time of our Founding Fathers. Every one of the leaders of the Democratic Party have strongly defended using filibusters in the past (which can easily be found such as on YouTube), but now that it benefits republicans, they want it stopped immediately.
Do they have an ounce of integrity? No. Are they shameless? Yes. And this is a very dangerous position for our country to be in because they've chosen Party over country. They want the influence and power. This is why it's so hard to get them out of office because they lie, cheat, and steal, to keep their lucrative jobs.
Side note: The longest filibuster on record comes from Senator Strom Thurmond in 1957 over the Civil Rights Act when he held the floor for 24 hours and 18 minutes. What an amazing accomplishment.