If James Carville from former President Bill Clinton's campaign staff was working for the Vikings he might utter the phrase: "It's the offensive line, stupid!" Just like a strong economy can fuel election to the White House, a strong offensive line helps coaches keep their jobs. The Vikings need to focus on their offensive line.

It's not that general Rick Spielman and head coach Mike Zimmer haven't paid attention to the offensive line. It's just that they have yet to improve it (on paper) over how it finished the season in 2014. In fact, more players are gone from that line than have been added.

Thus far, the Vikings have made the following moves on the offensive line:

* On Feb. 27 the Vikings released 2014 starting left guard Charlie Johnson. At 30, Johnson was aging, his skills were declining and he was making too much (a $2,500,000 cap hit) for his production. It was the right move, but the Vikings should have had a solid plan to replace him.

* On March 11 they re-signed versatile backup center/guard Joe Berger, who can play multiple positions on the line. It was necessary for depth, but he should be a starter only if all other plans fail.

* The team made a big swing at one of the top guards in free agency, Cincinnati's Clint Boling, and missed, leaving a gaping hole on the left side of the unfilled.

* Then on March 16 last year's backup guard Vladimir Ducasse, who filled in for the injured Brandon Fusco, signed a one-year contract with the Chicago Bears. It is not a huge loss, as Ducasse has only 11 starts in 63 games in five seasons and gave way to other back ups last year.

* That was followed on March 17 by the Vikings announcing they had re-signed swing tackle Mike Harris. Harris filled in for Phil Loadholt last season and even played some guard for the team. Harris comes back on a one-year deal, and he told the Pioneer Press he was happy to return and will play wherever the team needs him to play:

"It's a place where I feel like I can grow as a player," Harris said. "They've got a great coaching staff, especially [offensive coordinator] Norv Turner. Offensively, it's just going to get better this year, and I just want to be part of it. I'm just happy they have the confidence in me and they believe in me and want me on the team.''

So to tally things up, the Vikings have two starters returning from significant injuries (guard Fusco and tackle Loadholt both suffered season-ending torn pectorals) a left tackle who struggled last season in Matt Kalil, center John Sullivan who is solid but will be 30 on opening weekend and a backup in Berger who is probably the starting left guard by default.

That leaves Harris on the bench with three other tackles on the roster (Austin Wentworth, Antonio Richardson and Carter Bykowski) who have a total of two seasons of NFL experience. At guard the backups are David Yankey and Jordan McCray, who failed to see the field in their rookie seasons.

Now, perhaps the Vikings staff feels confident enough in these young players (with limited experience) to step in at a moment's notice this season, and that is why they didn't push harder to fill Johnson's left guard spot with an expensive blue chip free agent (Boling, Orlando Franklin or Mike Iupati, for instance).

But I would rather see Berger and Harris again being the first line backups and then fill in with the younger developing players. It says something that with all the injuries last season, Yankey didn't get on the field in a game.

The truth of the matter is, however, that the line played better during the last quarter of the season. Quarterback Teddy Bridgewater appeared to have more time to throw downfield, which is in partly attributable to his development, but the line deserves some credit, as well.

At season's end, Berger and Harris were in the line-up with Kalil, Sullivan and Johnson—so they contributed to the unit's improved play. That, for me, makes the re-signings of those two backups good moves, but I was hoping for a little more. Had the Vikings grabbed a decent starting guard in free agency, they would have been able to avoid addressing it in the first round of the draft.

But now I believe that is what they are left with. Perhaps that was the plan: take a chance with a top guard in free agency (Boling), but don't break the bank acquiring him. If he bites, great; if not, so be it. And if they don't get him, then Berger becomes an even bigger priority.

The team (with its apparent plan to build a young team from the draft and not over-spend on aging veterans) will likely try to grab an offensive lineman at No. 11 in the April draft. In our last mock draft at Vikings Journal, Bo Mitchell had the Vikings selecting Brandon Scherff, offensive tackle from Iowa.

I am good with that—I have long advocated getting younger and better on the line and that starts with the draft—but it amazes me how one's perceptions and desires change as things progress, including my own. I was all in on Boling, which I thought would allow the Vikings to grab a wide receiver or cornerback at No. 11. But the Viking missed on Boling and then traded for wide receiver Mike Wallace (and cut Greg Jennings), so the focus reverts back onto the offensive line.

There are several free agent guards still available, including Stefan Wisniewski from Oakland. Wisniewski visited some teams, but that list of teams thus far has not included the Vikings. Should it? I would say given the importance of the line, the big hole at guard and the fact that Wisniewski can also play center, he is worthy of the Vikings at least kicking the tires on him.

Head over to Vikings Journal to check out AJ Mansour's story on Trae Waynes and Bo Mitchell's early fantasy football rankings and then join in the conversation on the Vikings Journal forums, where everything Purple is dissected and discussed.

Joe Oberle is a senior writer at VikingsJournal.com, covers the NFL for The Sports Post and is managing editor of Minnesota Golfer magazine. He is an author and longtime Minnesota-based writer.