WASHINGTON—President Barack Obama's State of the Union address is fast approaching, and this year everyone is scrambling for a date.

In keeping with a nationwide appeal for more civil behavior following the Tucson shootings, Democratic and Republican lawmakers plan to mingle for Tuesday's State of the Union address. WSJ's Naftali Bendavid says that will make for some odd pairings.

No matter who is in the White House, the speech can be relied upon to provide television images of lawmakers on one side of the aisle applauding ardently for their party's president as their sullen colleagues across the divide sit on their hands.

Democratic Sen. Chuck Schumer, above, will sit with Republican Sen. Tom Coburn. Getty Images

This year, some lawmakers worried that partisan overtones would seem off-key after the Jan. 8 shootings in Tucson, Ariz, that targeted Rep. Gabrielle Giffords. So, a collection of cross-party pairs—odd couples, you might call them—are announcing plans to sit next to each other for the Tuesday event.

Sen. Tom Coburn Getty Images

Sen. Pat Toomey, a Republican, said he would sit with his Pennsylvania colleague, Democratic Sen. Bob Casey. House Majority Whip Kevin McCarthy (R., Calif.) said he would be happy to pair up with House Democratic Whip Steny Hoyer (D., Md.).

On Friday, Sen. Kirsten Gillibrand (D., N.Y.) announced she would take a seat alongside Sen. John Thune (R., S.D.). "This is just a symbol, but it sends an important message that…we all stand ready to work together," Ms. Gillibrand said.

Seating for the State of the Union speech has always been open, but Republicans traditionally sit on one side of the chamber and Democrats on the other. The push for a change began after the Tucson attack, in which six people were killed and 13 wounded, including Ms. Giffords, and Arizona Democrat.

The centrist Democratic group Third Way sent a letter to congressional leaders urging the bipartisan seating. "This will be the first time it's ever been done," said Jim Kessler, the group's vice president for policy.

Democratic Rep. Steny Hoyer, above, will pair with Republican Rep. Kevin McCarthy during Tuesday's speech. Getty Images

Mr. Kessler said he initially wasn't sure if the idea would be ridiculed or embraced. But Sen. Mark Udall (D., Colo.) picked up on the suggestion and began promoting it to his colleagues.

Now, lawmakers are scrambling, prom-like, to announce which ideologically incompatible colleague they will be joining for the big night.

Rep. Kevin McCarthy Getty Images

Sens. Chuck Schumer (D., N.Y.) and Tom Coburn (R., Okla.), ideological and stylistic opposites, said they would sit together.

Sen. Mary Landrieu (D., La.), who leads the Small Business Committee, announced she would sit with her GOP counterpart, Sen. Olympia Snowe of Maine. Ms. Landrieu called it "a small reflection of the friendship Olympia and I share."

Illinois Sens. Dick Durbin, a Democrat, and Mark Kirk, a Republican, will also sit together.

The idea's supporters admitted it is symbolic in many ways, but they expressed hope that the effort leads to a deeper civility. And as is often the case when folks pair up, the question is what happens the morning after.

"The real test of bipartisanship will begin the next day," Mr. Durbin said, "when we go back to work to debate some of the most important issues of our time."

Write to Naftali Bendavid at naftali.bendavid@wsj.com