(NewsNation) — Republicans secured a House majority Tuesday and they appear to have done so by winning more votes overall than Democrats nationwide. But in order to understand this year’s national popular vote, some additional context is useful.

The Cook Political Report’s national popular vote tracker currently shows Republicans winning 51.4% of House votes compared to Democrats’ 47.1% — a 4.3% gap that works out to about 4.4 million votes. That margin could narrow as votes continue to be counted in places like California, but it seems likely Republicans will win the popular vote by at least a couple of points.

If the GOP ends up winning 220 House seats, they’ll control just 50.6% of seats — a proportion that will likely be lower than their share of the popular vote. So why didn’t Republicans win more seats?

Here are three things to understand about this year’s overall vote and why it probably isn’t the best metric to gauge 435 distinct, regional races.

Uncontested races

Significantly more Republicans (13) than Democrats (3) ran unopposed for their congressional seats this year.

In Arizona’s 9th Congressional District, GOP incumbent Rep. Paul Gosar received more than 190,000 votes with no opponent. In Pennsylvania, two Republican incumbents took home nearly 500,000 votes while running uncontested.

By comparison, just three Democratic candidates ran unopposed, one each in Illinois, Massachusetts and New York.

In total, unopposed Republican congressional candidates have earned more than 1.9 million votes, compared to unopposed Democrats with just over 460,000 as of Wednesday, according to an analysis of Decision Desk HQ election data.

That marks a net difference of 1.44 million votes in favor of Republican candidates, which accounts for approximately one-third of the current popular vote gap.

It’s worth noting that in Florida and Louisiana — which each had a Republican incumbent run unopposed — votes are not counted for uncontested races. Therefore, GOP votes are slightly undercounted in the overall tally because those totals aren’t included.

The number of uncontested races in 2022 was more skewed toward the GOP relative to 2020, when six Republicans and five Democrats ran without an opponent, according to 270ToWin.com.

No major party opponent

Republicans were also more likely than Democrats to face third-party opponents in 2022.

In 10 U.S. House races, GOP incumbents faced third-party candidates, compared to three contests for Democrats.

That doesn’t mean an opponent from a major party would have outperformed the third-party alternative, it simply means Democrats and Republicans were unable to add to their party’s total popular vote margin in 13 races.

The GOP picked up nearly 400,000 votes in Florida’s 6th and 18th Congressional District races against third-party opponents. Likewise, in Texas’s 19th and 26th Congressional Districts, where Republicans added more than 330,000 votes to their national popular vote total.

As of Wednesday, Republican candidates have received more than 1.84 million votes in races against third-party candidates, compared to just over 500,000 for Democrats in similar battles — a net difference of 1.34 million votes in favor of Republicans.

That gap accounts for approximately 30% of today’s popular vote margin.

Same-party opposition

In a few states, multiple candidates from the same party can appear on the ballot. This further distorts the overall vote picture.

In California’s 16th Congressional District, Democratic incumbent Rep. Anna Eshoo defeated her Democratic challenger, Rishi Kumar. With no Republicans on the ballot, all 225,000 votes that have been counted go toward Democrats in the popular vote tally.

In total, six congressional races in California saw Democrats face off against members of their own party. This resulted in more than 830,000 votes going toward the Democratic national total, with votes still being counted as of Wednesday.

Louisiana is the other outlier. The Pelican State uses a majority-vote system, which means multiple candidates from the same party can appear on the Election Day ballot. If any candidate receives more than 50% of the vote, then they win the seat. If not, then the seat heads to a runoff election.

For example, the GOP earned nearly 170,000 votes across three candidates in the race to represent the state’s 5th Congressional District. Democrats received approximately 55,000 votes spread across two candidates in that same race.