House Democrats won’t vote for the new ranking member of the House Energy and Commerce Committee until after the midterm elections, but the two lawmakers vying for the slot have already begun courting colleagues and claiming supporters.

On Thursday, Rep. Anna G. Eshoo, D-Calif., received a big endorsement from a close friend and fellow Californian who also happens to be the caucus’s top Democrat: Minority Leader Nancy Pelosi.

“I strongly endorse Anna Eshoo to become the top Democrat on the Energy and Commerce Committee,” Pelosi said in a letter to colleagues obtained by CQ Roll Call. “It had not been my intention to make a public endorsement, but since so many of you have asked, I am writing to let you know why I support Anna.”

Pelosi listed many plaudits for Eshoo to succeed retiring Energy and Commerce ranking member Henry A. Waxman of California, concluding with a nod to Eshoo’s “leadership, vision, values and progressive commitment to the future [that] gives us the opportunity to newly invigorate the debate.”

Just the night before, Eshoo was the guest of honor at a meet and greet at Sona Creamery and Wine Bar on Capitol Hill. According to the official invitation to the event obtained by CQ Roll Call, the gathering was hosted by Rep. Jared Polis, D-Colo., and co-hosted by California Democrats Scott Peters, Adam B. Schiff, Ami Bera, Juan C. Vargas and Lois Capps. Other co-hosts included Reps. Elizabeth Esty and Joe Courtney of Connecticut, Terri A. Sewell of Alabama, Ann McLane Kuster of New Hampshire and Adam Smith of Washington.

“It was an event … on behalf of her Energy and Commerce candidacy,” an Eshoo spokesman confirmed.

But Eshoo’s rival, Rep. Frank Pallone Jr., D-N.J., won’t be outdone. On Thursday night, he will be the guest of honor at a dinner at Hunan Dynasty, a Chinese restaurant also local to Capitol Hill. The host? Congressional Hispanic Caucus Chairman Rubén Hinojosa, D-Texas.

A House Democratic aide confirmed that the Pallone dinner was taking place, while a spokeswoman for Hinojosa did not immediately respond to a request for comment.

Though Pelosi’s endorsement was not surprising, her public support now gives Eshoo a strong advantage. Eshoo also exhibits an edge among the California delegation and has some moderate lawmakers’ support under her belt, too, such as those hailing from the New Democrat Coalition.

But Pallone — who started making calls to potential supporters ahead of Eshoo in the pivotal hours after Waxman’s retirement announcement — is two notches above Eshoo in panel seniority, no small thing in a House Democratic Caucus where members put significant stock in tenure.

The Congressional Hispanic Caucus is especially adamant about honoring seniority in committee assignments to ensure against slights — accidental or intended — to minority lawmakers who might be next in line for plum committee assignments. The CHC chairman’s support for Pallone at this stage suggests that this tradition lives on.

Congressional Black Caucus Chairwoman Marcia L. Fudge, D-Ohio, has not yet signaled whom she will endorse, but her predecessor, Rep. Emanuel Cleaver II, D-Mo., said he imagined she, along with “every other African-American” in Congress, would agree with him: Seniority must be respected in doling out panel leadership slots.

“Seniority is of enormous importance to the CBC,” Cleaver told CQ Roll Call shortly after Pelosi sent out her letter on Eshoo’s behalf. “We would be trying to bite our own tails if we abandoned seniority.”

Cleaver conceded he could not speak for all CBC members, but said he expects the majority of the caucus will ultimately back Pallone.

Rep. Charles B. Rangel, D-N.Y., a CBC member, said that Pelosi, in her letter endorsing Eshoo, “officially buried seniority.”