Today, Tim Kaine is the junior senator from the Commonwealth of Virginia—one of one hundred members that comprise the U.S. Senate. In about a month, however, Kaine could very well be Secretary Hillary Clinton's vice-presidential running mate.

Politico and the Washington Post are both reporting that the Clinton campaign is now smack in the middle of vetting candidates for the number-two slot. In addition to Sen. Kaine, the Clinton camp is taking a good, hard look at Massachusetts Sen. Elizabeth Warren and Housing and Development Secretary Julian Castro as possible runningmates—two individuals who would inspire the progressive base of the Democratic Party that helped carry the insurgent campaign of Bernie Sanders towards primary wins in twenty-two states. Sen. Sherrod Brown, Rep. Xavier Bacerra, Sen. Cory Booker, Labor Secretary Thomas Perez and Retired Admiral Mike Mullen are names that have also been rumored to be on Secretary Clinton's mind, although none of these individuals have confirmed to the media that they are indeed being considered as vice presidential nominees.

At fifty-eight years of age, Kaine doesn't represent the youthful, progressive, up-and-coming wing of the Democratic Party that became so prevalent this year and large and vocal faction that dominated the conversation during the Democratic primary. He doesn't have the oratory gifts of a Bill Clinton or Barack Obama.

What Tim Kaine does have, however, is a near-universal respect from his colleagues in the Senate; a pragmatic streak that Hillary Clinton could surely appreciate; executive and legislative experience under his belt (Governor of Virginia from 2006–10, Senator from Virginia, 2012-present); and a deep relationship with the Democratic Party (Chairman of the Democratic National Committee, 2009–11).

As a member of the Senate Armed Services and Foreign Relations Committees, Kaine has become one of the most knowledgeable Democrats on issues of foreign policy and national security. He tries to stay away from partisan politics when drafting foreign policy legislation or discussing the military campaign against ISIS in floor speeches. His defense of the Iranian nuclear agreement last summer may have been an exception, but his decision to call out congressional Republicans was more to expose their staunch opposition to the deal and the political way in which many Republicans based their objections rather than embarrassing his colleagues by scoring political points.

With all of this in mind, Kaine's best quality may be his willingness to go places where many of his Senate colleagues refuse to go. In vivid contrast to the House and Republican leadership and some members of his own party, Kaine has been (and remains) a persistent advocate of getting the legislative branch back into the business of war and peace. This means, first and foremost, drafting, debating, and voting on a new authorization for the use of military force (AUMF) that would provide President Obama and his successor the statutory authority to actually prosecute the war against ISIS under the U.S. Constitution. Kaine's advocacy for a new AUMF borders on the obsessive; he rails against his colleagues for not fulfilling the most important duty that the Congress is granted under the Constitution. His latest attempt at forcing the Senate to the replace or revise the fifteen-year old AUMF currently on the books—attaching two amendments to the 2017 National Defense Authorization Act—ended in failure when the entire amendment process on the bill collapsed in gridlock. But it's highly unlikely that Kaine will stop his crusade just because he's run up against congressional dysfunction; he could very well try to attack his AUMF measures to upcoming appropriations bills. The fact that those amendments will face the same roadblock won't discourage him because the putting Congress on record is that important. It will be interesting to see if he pursues this cause with the same vigor if he comes vice president.