Can Ted Cruz go from obstructionist in chief to commander in chief?

Sen. Ted Cruz announced his presidential bid with a tweet early Monday, and among the key questions he will face in a GOP field potentially stacked with sitting and former governors is what accomplishments he can point to from his brief tenure in the U.S. Senate — and whether he can run largely on his very active role in slowing the governing body to a legislative standstill.

Since winning election in 2012, the junior senator from Texas has developed a reputation as a key foe of the president’s and has earned attention for what he has stopped the Senate from doing rather than for proactive legislating or novel policy proposals. To be sure, in today’s deadlocked Congress — where very few bills ever make it to the president’s desk for approval (or a veto) — Cruz is not alone in having a thin record of legislative accomplishment.

But only one bill sponsored by Cruz has become a U.S. law — and it was a narrowly targeted piece of legislation that came out of the Judiciary Committee, upon which he serves, to uncontroversially deny “admission to the United States to any representative to the United Nations who has been found to have been engaged in espionage activities or terrorist activity against the United States.” The bill passed in Cruz’s second year in office.

Cruz also has been a cosponsor of two bills, one led by Democrat Barbara Boxer of California and another by Republican Roy Blunt of Missouri, that became law last year: the United States-Israel Partnership Act of 2014, which had 80 cosponsors, and the Near East and South Central Asia Religious Freedom Act of 2014, which had 22 cosponsors, respectively.

With so few pieces of legislation to take credit for, the key discussion over Cruz and the Senate will have to be about his approach while there: How has he tried to shape the rare piece of legislation with a chance of becoming law as it passed through the upper chamber?

On that question, Cruz has succeeded more as a disruptive force than as a savvy legislative tactician. His approach stands in marked contrast to that of Sen. Rand Paul, R-Ky., another conservative senator mulling a presidential bid. Though Cruz and Paul, especially in Cruz’s first months in the Senate, were often lumped into the same category as firebrands with strong beliefs, their dealings inside the Senate and with their colleagues have in fact set them apart from each other.

Cruz is best known for his role in shutting down the federal government in October 2013, when he devised and executed a strategy of blocking any spending bill that included funds that would be used toward implementing the president’s health care law. He united House and Senate conservatives to keep the government shuttered for more than two weeks, which cost the economy billions of dollars, according to the Office of Management of Budget, and angered fellow Republicans who saw no endgame in the strategy other than a dip in the party’s approval rating. Cruz, however, gained significant star power within the conservative base through the shutdown and has since hewn to the combative course he set during his first year in office.

As recently as December 2014, Cruz upset his fellow senators by delaying a deal to avert another government shutdown. In blocking a deal between Senate leaders to clear a year-end spending bill because he did not want any legislation to fund Obama’s executive action on immigration, Cruz forced his colleagues to return to Washington for a series of procedural votes that would not have been needed without his actions. GOP frustration with Cruz was both personal — Cruz was cutting into senators’ holiday breaks — and practical, as there was no actual legislative way to defund Obama’s unilateral immigration policy, because the agency that oversees it is independent of congressional appropriation. That made Cruz’s move an entirely symbolic one.

Cruz has not been shy in criticizing Senate Majority Leader Mitch McConnell and has often disregarded the party’s interests, because Cruz’s own interests have run counter to those of the GOP establishment. To date, he has not had to be part of an effective governing majority.

In contrast, Paul leveraged his conservative credentials into a politically expedient relationship with McConnell, also of Kentucky, and promoted conservative ideas by writing bills and forcing McConnell to hold votes on them as amendments to the few bills that need to pass every year.

In Congress, it’s called “finding a vehicle,” which means taking a bill that must pass each year, like a spending bill or a crucial program authorization — the vehicle — and using it as an opportunity to vote on mostly unrelated amendments in a bid to force them into law. If the big spending bills are giant ships, think of these amendments as barnacles that can pass through open shipping channels if first secured to a vessel’s side.

Paul was a more active and more successful adopter of the legislative amendment strategy than Cruz has been so far. In his first two years in Congress, Paul sponsored 176 amendments — and he has pushed a total of 292 amendments in his just-over-four-year Senate career, according to statistics kept by the Library of Congress. Sixty-nine of those amendments were acted on by the Senate, meaning they either came up for votes or were adopted by consent. Cruz, for his part, has sponsored 107 amendments — 103 of them in his first two years. But only 13 of those amendments were acted upon by the Senate.

Both Cruz and Paul serve on the Senate Judiciary Committee and have focused significantly on judiciary issues. The committee has given them a platform to talk about issues that draw unique bipartisan support, such as bills trying to limit the government’s ability to collect data from American citizens or drug sentencing reform. Democrats enjoy partnering with Cruz and Paul on these issues because they are able to bring the attention of the conservative political base to a topic, which can spur more establishment Republicans to action.

As Cruz becomes the first Republican to formally announce his candidacy for the White House, it remains an open question whether he will change his course in Congress in the year ahead. As Yahoo News previously reported, even as Cruz gave a fiery speech at the Conservative Political Action Conference in Washington last month, he allowed the Senate to proceed on a bill to fund the Department of Homeland Security and avoid a shutdown of the key agency. At the time, Senate aides noted that Cruz’s presidential ambitions might have played a role in that action, though his own aides denied it.

The Senate will not have to vote again to fund the government until September, which gives the senator a bit of time to plot out his next move — in the Republican presidential primary and in Washington.