After finishing law school in 1985, Merz worked as a judge and corporate lawyer before entering full-time politics in 1989 when he was elected to the European Parliament.

[6][7] As a young politician in the 1970s and 1980s, he was a staunch supporter of anti-communism, the dominant state doctrine of West Germany and a core tenet of the CDU.

[20][21] After finishing his Abitur exam in 1975 Merz served his military service as a soldier with a self-propelled artillery unit of the German Army.

In 1986 he left his position as a judge in order to work as an in-house attorney-at-law at the German Chemical Industry Association in Bonn and Frankfurt from 1986 to 1989.

In October 1998 Merz became vice-chairman and in February 2000 Chairman of the CDU/CSU parliamentary group (alongside Michael Glos), succeeding Wolfgang Schäuble.

Ahead of the 2002 elections, Edmund Stoiber included Merz in his shadow cabinet for the Christian Democrats' campaign to unseat incumbent Schröder as chancellor.

[30] He has also taken on numerous positions on corporate boards, including the following: Between 2010 and 2011, Merz represented the shareholders of WestLB, a publicly owned institution that had previously been Germany's third-largest lender, in talks with bidders.

[43] In November 2017, Merz was appointed by Minister-President Armin Laschet of North Rhine-Westphalia as his Commissioner for Brexit and Transatlantic Relations, an unpaid advisory position.

[4] His candidacy was promoted by the former CDU chairman and "crown prince" of the Kohl era, Wolfgang Schäuble (former President of the Bundestag, ranked second in federal precedence).

Laschet justified this by saying that Merz was "without doubt a team player" and that his economic and financial expertise could provide crucial help in overcoming the huge challenge of the pandemic in a sustainable way.

[54] Ahead of the 2021 German federal election, Patrick Sensburg, Merz's successor in his seat in the Bundestag, failed to secure his party's support for a new candidacy.

[8] As a young politician in the 1970s and 1980s, he was a staunch supporter of anti-communism, the dominant state doctrine of West Germany and a core tenet of the CDU.

Merz said that if he were elected Chancellor, on the first day of his term in office he would instruct the Federal Ministry of the Interior to "permanently control the German state borders," and, "to reject all attempts at illegal entry without exception."

[86] Merz opposed the Bürgergeld (unemployment payment) and, like the CDU,[87] wants to see it abolished and replaced by another system called New Basic Security.

On a TV talk show, he said that female teachers in German schools were experiencing a lack of respect from "little pashas," apparently referring to sons of Muslim parents and allegedly "xenophobic" remarks about rejected asylum seekers “social tourists” who come to Germany to “get their teeth done”.

Weeks before, Merz had referred to some displaced Ukrainians as "welfare tourists" and said that many had come to Germany seeking safety, only to then travel back and forth between both countries after securing social benefits, remarks that he later said he regretted.

[91][92][93][94] In the 1990s, Merz was in the minority even in his conservative CDU when he voted against liberalizing the abortion law, against preimplantation genetic diagnostics and criminalizing marital rape.

[93] Merz has been the chairman of the Atlantik-Brücke association which promotes German-American understanding and Atlanticism and is a staunch supporter of the European Union and NATO.

"[10] In 2023, Merz called for Germany to involve key allies, especially France, in negotiations with China as part of a rethink of ties with the country that reflected a global "paradigm shift" in security and foreign policy.

Merz said he would as chancellor try to bring about a European decision on the matter of the question whether to allow Ukraine to strike against targets deep within Russian territory with western weapons.

[104] In October 2024, Merz successfully urged the German government to resume weapons deliveries to Israel, including spare parts for tanks.

[106][107] He criticised the International Criminal Court's decision to issue an arrest warrant for Israeli Prime Minister Benjamin Netanyahu.

[77] In December 2024, after the Fall of the Assad regime in Syria, he called on Europe to strengthen its ties with Turkey "to bring political pacification to this region.

Merz went on to deny that time is running out for successful climate change measures, and that the country will be on the right track if it makes the right decisions over the next decade.

A month later, after being criticised over an apparent failure to implement his "announcement" from December 2021, he reiterated his differentiation regarding to political levels and claimed that in local parliaments "of course [...] we must look for ways to jointly shape the city, the state and the district.

[121][120] Minister-President of Saxony, Michael Kretschmer (CDU), however, declared that a refusal of cross-party cooperation in substantive decisions at the local level was not sustainable in a democracy.

As a result, an agreement was reached that members of parliament should disclose their income from secondary activities in order to give the public an opportunity to assess whether their representatives may be harmfully dependent and influenced by financial contributions from third parties.

At the hearing in October 2006, Merz pointed out that according to Article 38 of the Basic Law of Germany (constitution), members of parliament are "not bound by instructions and are subject only to their conscience".

He said that the regulation would drive many MPs into career politics, which is far removed from real life, even though secondary activities are not prohibited, but only the number and amount of their fees should be disclosed.

In July 2007, the Federal Constitutional Court rejected the lawsuit by a vote of four to four, on the grounds that the political mandate must be "at the center of the activity" and criticized the risk of bias due to payments from companies.