Sen. Elizabeth Warren (D-MA). Her progressive credentials and her appeal as a campaigner and as an attack dog against Trump are well known. Three potential drawbacks: Most important is: How do she and Clinton get along personally? Would her exuberant style overshadow Clinton; would her own agenda be in conflict with Clinton's? On the other hand, maybe it's Warren, more than Sanders, who is influencing Clinton in more progressive positions. We'll get a preview of that when they campaign together in Cincinnati on Monday. One concern is that a Republican governor would appoint her senate replacement. But Massachusetts allows for a special election in a very short time, so it could be temporary, possibly even before she becomes VP in January. But also remember that our "bluest state" has elected Republican governors several times in recent years, and they elected Scott Brown to replace Ted Kennedy. Warren is my first choice in many ways; and the cautions have nothing to do with her personally, just the logistics and the chemistry with Clinton.
Sen. Tim Kaine (D-VA). Senator Kaine was a popular governor and now senator of the battleground state Virginia. He's a good solid, moderate Democrat, which for me may be the major drawback. In the post-Sanders era, Clinton needs to have someone who can appeal to Sanders voters. She's got all the "moderate" credibility that she needs. I don't think Kaine adds anything there. Not a lot of charisma like the other two either. Otherwise, I think he's a fine choice, especially because he seems authentic and sincere. Virginia has a Democratic governor to name his replacement. One pundit believes Kaine is the most likely pick.
Secretary of Housing Julian Castro (D-TX). His big favorables: Clinton likes him and seems energized by him. I saw video footage of them together from campaign events, and Clinton glows in his presence. Besides: He is Hispanic, young with an attractive family, and has an inspiring personal story (single mother from Mexico raising twin sons, who both went to Stanford and then Harvard Law school -- and made good: one a big city mayor and then Obama's cabinet; the other a U.S. Congressman). Julien was mayor of San Antonio when he wowed the audience with his keynote address at the 2012 Democratic convention. Obama put him in his second term cabinet, dealing with major urban issues of housing. So he has a little Washington experience, but not too much. Drawback: I'm not sure how effective an attack dog he would be against Trump; but then Clinton is doing a pretty good job of that on her own. If Julian makes her glow, then I'm for that.
We need to remember this is not an announcement from the Clinton camp. It could be a strategic leak to distract from the real person they're going for. Who knows? All we can say is that more than one source (AP and CNN) are reporting that these three are on the vetting list. They didn't say whether there will be others.
Three others who have been frequently mentioned in the media are Sen. Sherrod Brown (D-OH), who would bring a progressive track record, popularity in the most important swing state of Ohio, and someone Clinton obviously likes and feels comfortable with. He has a deceptively old-shoe, rumpled-suit, gravel-voiced quality to him that tends to mask a keen intelligence and a savvy politician. Main drawback: his replacement in the senate would be appointed by Republican governor John Kasich. And I don't know how soon they would hold an election.
The other frequent mentions are two more Hispanics: Rep. Xavier Becerra (D-CA) and Labor Secretary Tom Preez. I know that Perez was a noted civil rights activist and labor attorney before joining Obama's second-term cabinet. Becerra is a Stanford Law School grad, who worked his way up to Deputy Attorney General of California, and was then elected to the House. Obviously well-liked by colleagues, since he is currently Chair of the House Democratic Caucus.