Politics is now more important for daters. A relationship expert shares tips.

Online daters are used to swiping right or left — but could their decision hinge on whether that person leans right or left politically?

Political views of a potential partner are becoming more important for daters, Terri Orbuch, a relationship expert at DatingAdvice and professor of sociology at Oakland University, tells CBS News — but often singles don't know how to approach the subject.

"They don't bring it up on the first or even the second date, and then all of a sudden, the third date occurs, and bam, they have these political differences," she said.

Here's what to keep in mind when it comes to politics and dating.

Why political differences matter in relationships

"Our identities and who we see ourselves as are tied to these issues that have now become political, which are issues of social justice and diversity and inclusion and equity, gender, race, sexual orientation," Orbuch said.

It's not necessarily who you're voting for or if you're a Democrat or Republican, either.

"We're really talking about underlying values and issues that are important to individuals and values and attitudes that are important to your identity," she said.

The same is true when it comes to relationships with family and friends , which experts say can be another difficult situation to navigate.

When it comes to romantic relationships, these values can be a key determiner of compatibility — something Orbuch has seen firsthand as the director of a long-term study funded by the National Institutes of Health that has been following more than 300 couples for over 35 years to determine what keeps them together.

"It is significant to have similarity with your partner (on your top two key life values) if you want longevity in your relationship. It is extremely important," she said.

In addition to issues of social justice, diversity and inclusion, other key life values include importance of children and family, your approach to money and approach to health and fitness.

The inverse is also true. If politics-leaning issues of social justice are not one of your top two key life values, then having that similarity with a potential partner is not key to compatibility and long term longevity, she explained. Instead, you'd want similarities with the other values that are more important to you.

Tips to bring up "politics" in dating

So, how do you bring up politics during a date if issues tied to it are important to you? Orbuch said it's better to focus on the underlying values you're looking for in a partner.

To do this, she suggests a three-step approach:

1. Observe behaviors: "What you really want to do at this first step is observe their behaviors and how they interact, talk with other people," said Orbuch. "How are they talking to the barista, the server, the person that is seating you? Are they respectful? Are they looking at them? Are they talking to them respectfully? Are they tipping?"

2. Ask life questions: Instead of direct questions about politics, ask questions that reveal what they value in life. For example, what does their ideal weekend look like? What do they like to do outside of work?

"These are great questions to get answers about a whole lot of topics, but I also think you can get answers to how they value ideas about social justice, diversity and inclusion," she said.

3. Share your own experiences: Lastly, you can reveal what you value by sharing your own interests.

To show you value family, for example, you might say, "I love my niece ... so I volunteered yesterday at her school to read a story," Orbuch said.

Seeing how the other person responds, she said, even by observing their nonverbal reactions, will tell you a lot about whether they hold similar key life values.

Political filters on dating apps

The three-step approach is great if you don't know someone's political leanings or values, but Orbuch understands using filter options now available on many dating apps to immediately set boundaries with certain political views — in fact, she said she's "an advocate of that."

"People have deal breakers, and when you are searching online and when you're doing the dating app, you can filter. Or there are even niche dating sites like if you want a certain religion, if you want a certain age," she said. "If you're on a dating app and people are acknowledging who they're going to vote for, acknowledging their political affiliation or acknowledging their key life value about an issue of social justice, then you can filter them out, because that's your deal breaker."